| 12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788899091929394959697989910010110210310410510610710810911011111211311411511611711811912012112212312412512612712812913013113213313413513613713813914014114214314414514614714814915015115215315415515615715815916016116216316416516616716816917017117217317417517617717817918018118218318418518618718818919019119219319419519619719819920020120220320420520620720820921021121221321421521621721821922022122222322422522622722822923023123223323423523623723823924024124224324424524624724824925025125225325425525625725825926026126226326426526626726826927027127227327427527627727827928028128228328428528628728828929029129229329429529629729829930030130230330430530630730830931031131231331431531631731831932032132232332432532632732832933033133233333433533633733833934034134234334434534634734834935035135235335435535635735835936036136236336436536636736836937037137237337437537637737837938038138238338438538638738838939039139239339439539639739839940040140240340440540640740840941041141241341441541641741841942042142242342442542642742842943043143243343443543643743843944044144244344444544644744844945045145245345445545645745845946046146246346446546646746846947047147247347447547647747847948048148248348448548648748848949049149249349449549649749849950050150250350450550650750850951051151251351451551651751851952052152252352452552652752852953053153253353453553653753853954054154254354454554654754854955055155255355455555655755855956056156256356456556656756856957057157257357457557657757857958058158258358458558658758858959059159259359459559659759859960060160260360460560660760860961061161261361461561661761861962062162262362462562662762862963063163263363463563663763863964064164264364464564664764864965065165265365465565665765865966066166266366466566666766866967067167267367467567667767867968068168268368468568668768868969069169269369469569669769869970070170270370470570670770870971071171271371471571671771871972072172272372472572672772872973073173273373473573673773873974074174274374474574674774874975075175275375475575675775875976076176276376476576676776876977077177277377477577677777877978078178278378478578678778878979079179279379479579679779879980080180280380480580680780880981081181281381481581681781881982082182282382482582682782882983083183283383483583683783883984084184284384484584684784884985085185285385485585685785885986086186286386486586686786886987087187287387487587687787887988088188288388488588688788888989089189289389489589689789889990090190290390490590690790890991091191291391491591691791891992092192292392492592692792892993093193293393493593693793893994094194294394494594694794894995095195295395495595695795895996096196296396496596696796896997097197297397497597697797897998098198298398498598698798898999099199299399499599699799899910001001100210031004100510061007100810091010101110121013101410151016101710181019102010211022102310241025102610271028102910301031103210331034103510361037103810391040104110421043104410451046104710481049105010511052105310541055 | <!DOCTYPE html><html><head>  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />  <title>The source code</title>  <link href="../resources/prettify/prettify.css" type="text/css" rel="stylesheet" />  <script type="text/javascript" src="../resources/prettify/prettify.js"></script>  <style type="text/css">    .highlight { display: block; background-color: #ddd; }  </style>  <script type="text/javascript">    function highlight() {      document.getElementById(location.hash.replace(/#/, "")).className = "highlight";    }  </script></head><body onload="prettyPrint(); highlight();">  <pre class="prettyprint lang-js"><span id='String'>/**</span> * @class String * * `String` is a global object that may be used to construct String instances. * * String objects may be created by calling the constructor `new String()`. The `String` object wraps * JavaScript's string primitive data type with the methods described below. The global function * `String()` can also be called without new in front to create a primitive string. String literals in * JavaScript are primitive strings. * * Because JavaScript automatically converts between string primitives and String objects, you can call * any of the methods of the `String` object on a string primitive. JavaScript automatically converts the * string primitive to a temporary `String` object, calls the method, then discards the temporary String * object. For example, you can use the `String.length` property on a string primitive created from a * string literal: * *     s_obj = new String(s_prim = s_also_prim = "foo"); * *     s_obj.length;       // 3 *     s_prim.length;      // 3 *     s_also_prim.length; // 3 *     'foo'.length;       // 3 *     "foo".length;       // 3 * * (A string literal is denoted with single or double quotation marks.) * * String objects can be converted to primitive strings with the `valueOf` method. * * String primitives and String objects give different results when evaluated as JavaScript. Primitives * are treated as source code; String objects are treated as a character sequence object. For example: * *     s1 = "2 + 2";               // creates a string primitive *     s2 = new String("2 + 2");   // creates a String object *     eval(s1);                   // returns the number 4 *     eval(s2);                   // returns the string "2 + 2" *     eval(s2.valueOf());         // returns the number 4 * * # Character access * * There are two ways to access an individual character in a string. The first is the `charAt` method: * *     return 'cat'.charAt(1); // returns "a" * * The other way is to treat the string as an array, where each index corresponds to an individual * character: * *     return 'cat'[1]; // returns "a" * * The second way (treating the string as an array) is not part of ECMAScript 3. It is a JavaScript and * ECMAScript 5 feature. * * In both cases, attempting to set an individual character won't work. Trying to set a character * through `charAt` results in an error, while trying to set a character via indexing does not throw an * error, but the string itself is unchanged. * * # Comparing strings * * C developers have the `strcmp()` function for comparing strings. In JavaScript, you just use the less- * than and greater-than operators: * *     var a = "a"; *     var b = "b"; *     if (a < b) // true *         print(a + " is less than " + b); *     else if (a > b) *         print(a + " is greater than " + b); *     else *         print(a + " and " + b + " are equal."); * * A similar result can be achieved using the `localeCompare` method inherited by `String` instances. * * <div class="notice"> * Documentation for this class comes from <a href="https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/String">MDN</a> * and is available under <a href="http://creativecommons.org/licenses/by-sa/2.0/">Creative Commons: Attribution-Sharealike license</a>. * </div> */<span id='String-method-constructor'>/**</span> * @method constructor * Creates new String object. * @param {Object} value The value to wrap into String object. *///Methods<span id='String-method-fromCharCode'>/**</span> * @method fromCharCode * Returns a string created by using the specified sequence of Unicode values. * * This method returns a string and not a `String` object. * * Because `fromCharCode` is a static method of `String`, you always use it as `String.fromCharCode()`, * rather than as a method of a `String` object you created. * * Although most common Unicode values can be represented in a fixed width system/with one number (as * expected early on during JavaScript standardization) and `fromCharCode()` can be used to return a * single character for the most common values (i.e., UCS-2 values which are the subset of UTF-16 with * the most common characters), in order to deal with ALL legal Unicode values, `fromCharCode()` alone * is inadequate. Since the higher code point characters use two (lower value) "surrogate" numbers to * form a single character, `fromCharCode()` can be used to return such a pair and thus adequately * represent these higher valued characters. * * Be aware, therefore, that the following utility function to grab the accurate character even for * higher value code points, may be returning a value which is rendered as a single character, but * which has a string count of two (though usually the count will be one). * *     // String.fromCharCode() alone cannot get the character at such a high code point *     // The following, on the other hand, can return a 4-byte character as well as the *     //   usual 2-byte ones (i.e., it can return a single character which actually has *     //   a string length of 2 instead of 1!) *     alert(fixedFromCharCode(0x2F804)); // or 194564 in decimal * *     function fixedFromCharCode (codePt) { *         if (codePt > 0xFFFF) { *             codePt -= 0x10000; *             return String.fromCharCode(0xD800 + (codePt >> 10), 0xDC00 + *             (codePt & 0x3FF)); *         } *         else { *             return String.fromCharCode(codePt); *         } *     } * * The following example returns the string "ABC". * *     String.fromCharCode(65,66,67) * * @param {Number} num1, ..., numN A sequence of numbers that are Unicode values. * @return {String} String containing characters from encoding. *///Properties<span id='String-property-length'>/**</span> * @property {Number} length * Reflects the length of the string. * * This property returns the number of code units in the string. UTF-16, the string format used by JavaScript, uses a single 16-bit * code unit to represent the most common characters, but needs to use two code units for less commonly-used characters, so it's * possible for the value returned by `length` to not match the actual number of characters in the string. * * For an empty string, `length` is 0. * *     var x = "Netscape"; *     var empty = ""; * *     console.log("Netspace is " + x.length + " code units long"); *     console.log("The empty string is has a length of " + empty.length); // should be 0 *///Methods<span id='String-method-charAt'>/**</span> * @method charAt * Returns the character at the specified index. * * Characters in a string are indexed from left to right. The index of the first character is 0, and * the index of the last character in a string called `stringName` is `stringName.length - 1`. If the * index you supply is out of range, JavaScript returns an empty string. * * The following example displays characters at different locations in the string "Brave new world": * *     var anyString="Brave new world"; * *     document.writeln("The character at index 0 is '" + anyString.charAt(0) + "'"); *     document.writeln("The character at index 1 is '" + anyString.charAt(1) + "'"); *     document.writeln("The character at index 2 is '" + anyString.charAt(2) + "'"); *     document.writeln("The character at index 3 is '" + anyString.charAt(3) + "'"); *     document.writeln("The character at index 4 is '" + anyString.charAt(4) + "'"); *     document.writeln("The character at index 999 is '" + anyString.charAt(999) + "'"); * * These lines display the following: * *     The character at index 0 is 'B' *     The character at index 1 is 'r' *     The character at index 2 is 'a' *     The character at index 3 is 'v' *     The character at index 4 is 'e' *     The character at index 999 is '' * * The following provides a means of ensuring that going through a string loop always provides a whole * character, even if the string contains characters that are not in the Basic Multi-lingual Plane. * *     var str = 'A\uD87E\uDC04Z'; // We could also use a non-BMP character directly *     for (var i=0, chr; i < str.length; i++) { *         if ((chr = getWholeChar(str, i)) === false) {continue;} // Adapt this line at the top of * each loop, passing in the whole string and the current iteration and returning a variable to * represent the individual character *         alert(chr); *     } * *     function getWholeChar (str, i) { *         var code = str.charCodeAt(i); * *         if (isNaN(code)) { *         return ''; // Position not found *         } *         if (code < 0xD800 || code > 0xDFFF) { *             return str.charAt(i); *         } *         if (0xD800 <= code && code <= 0xDBFF) { // High surrogate (could change last hex to 0xDB7F * to treat high private surrogates as single characters) *         if (str.length <= (i+1))  { *             throw 'High surrogate without following low surrogate'; *         } *         var next = str.charCodeAt(i+1); *         if (0xDC00 > next || next > 0xDFFF) { *             throw 'High surrogate without following low surrogate'; *         } *         return str.charAt(i)+str.charAt(i+1); *     } *     // Low surrogate (0xDC00 <= code && code <= 0xDFFF) *     if (i === 0) { *         throw 'Low surrogate without preceding high surrogate'; *     } *     var prev = str.charCodeAt(i-1); *     if (0xD800 > prev || prev > 0xDBFF) { // (could change last hex to 0xDB7F to treat high private * surrogates as single characters) *       throw 'Low surrogate without preceding high surrogate'; *     } *     return false; // We can pass over low surrogates now as the second component in a pair which we * have already processed * } * * While the second example may be more frequently useful for those wishing to support non-BMP * characters (since the above does not require the caller to know where any non-BMP character might * appear), in the event that one _does_ wish, in choosing a character by index, to treat the surrogate * pairs within a string as the single characters they represent, one can use the following: * *     function fixedCharAt (str, idx) { *         var ret = ''; *         str += ''; *         var end = str.length; * *         var surrogatePairs = /[\uD800-\uDBFF][\uDC00-\uDFFF]/g; *         while ((surrogatePairs.exec(str)) != null) { *             var li = surrogatePairs.lastIndex; *             if (li - 2 < idx) { *                 idx++; *             } *             else { *             break; *         } *     } * *     if (idx >= end || idx < 0) { *         return ''; *     } * *     ret += str.charAt(idx); * *     if (/[\uD800-\uDBFF]/.test(ret) && /[\uDC00-\uDFFF]/.test(str.charAt(idx+1))) { *         ret += str.charAt(idx+1); // Go one further, since one of the "characters" is part of a * surrogate pair *     } *     return ret; *     } * * @param {Number} index An integer between 0 and 1 less than the length of the string. * @return {String} Individual character from string. */<span id='String-method-charCodeAt'>/**</span> * @method charCodeAt * Returns a number indicating the Unicode value of the character at the given index. * * Unicode code points range from 0 to 1,114,111. The first 128 Unicode code points are a direct match * of the ASCII character encoding. * * Note that `charCodeAt` will always return a value that is less than 65,536. This is because the * higher code points are represented by a pair of (lower valued) "surrogate" pseudo-characters which * are used to comprise the real character. Because of this, in order to examine or reproduce the full * character for individual characters of value 65,536 and above, for such characters, it is necessary * to retrieve not only `charCodeAt(i)`, but also `charCodeAt(i+1)` (as if examining/reproducing a * string with two letters). See example 2 and 3 below. * * `charCodeAt` returns `NaN` if the given index is not greater than 0 or is greater than the length of * the string. * * Backward Compatibility with JavaScript 1.2 * * The `charCodeAt` method returns a number indicating the ISO-Latin-1 codeset value of the character * at the given index. The ISO-Latin-1 codeset ranges from 0 to 255. The first 0 to 127 are a direct * match of the ASCII character set. * * Example 1: Using `charCodeAt` * * The following example returns 65, the Unicode value for A. * *    "ABC".charCodeAt(0) // returns 65 * * Example 2: Fixing `charCodeAt` to handle non-Basic-Multilingual-Plane characters if their presence * earlier in the string is unknown * * This version might be used in for loops and the like when it is unknown whether non-BMP characters * exist before the specified index position. * *     function fixedCharCodeAt (str, idx) { *         // ex. fixedCharCodeAt ('\uD800\uDC00', 0); // 65536 *         // ex. fixedCharCodeAt ('\uD800\uDC00', 1); // 65536 *         idx = idx || 0; *         var code = str.charCodeAt(idx); *         var hi, low; *         if (0xD800 <= code && code <= 0xDBFF) { // High surrogate (could change last hex to 0xDB7F to treat high private surrogates as single characters) *             hi = code; *             low = str.charCodeAt(idx+1); *             if (isNaN(low)) { *                 throw 'High surrogate not followed by low surrogate in fixedCharCodeAt()'; *             } *             return ((hi - 0xD800) * 0x400) + (low - 0xDC00) + 0x10000; *         } *         if (0xDC00 <= code && code <= 0xDFFF) { // Low surrogate *         // We return false to allow loops to skip this iteration since should have already handled * high surrogate above in the previous iteration *             return false; *         } *         return code; *     } * * Example 3: Fixing `charCodeAt` to handle non-Basic-Multilingual-Plane characters if their presence * earlier in the string is known * *     function knownCharCodeAt (str, idx) { *         str += ''; *         var code, *         end = str.length; * *         var surrogatePairs = /[\uD800-\uDBFF][\uDC00-\uDFFF]/g; *         while ((surrogatePairs.exec(str)) != null) { *             var li = surrogatePairs.lastIndex; *             if (li - 2 < idx) { *                 idx++; *             } *             else { *                 break; *             } *         } * *         if (idx >= end || idx < 0) { *             return NaN; *         } * *         code = str.charCodeAt(idx); * *         var hi, low; *         if (0xD800 <= code && code <= 0xDBFF) { *             hi = code; *             low = str.charCodeAt(idx+1); // Go one further, since one of the "characters" is part of * a surrogate pair *             return ((hi - 0xD800) * 0x400) + (low - 0xDC00) + 0x10000; *         } *         return code; *     } * * @param {Number} index An integer greater than 0 and less than the length of the string; if it is * not a number, it defaults to 0. * @return {Number} Value between 0 and 65535. */<span id='String-method-concat'>/**</span> * @method concat * Combines the text of two strings and returns a new string. * * `concat` combines the text from one or more strings and returns a new string. Changes to the text in * one string do not affect the other string. * * The following example combines strings into a new string. * *     var hello = "Hello, "; *     console.log(hello.concat("Kevin", " have a nice day.")); // Hello, Kevin have a nice day. * * @param {String} string2...stringN * @return {String} Result of both strings. */<span id='String-method-indexOf'>/**</span> * @method indexOf * Returns the index within the calling `String` object of the first occurrence of the specified value, * or -1 if not found. * * Characters in a string are indexed from left to right. The index of the first character is 0, and the index of the last character * of a string called `stringName` is `stringName.length - 1`. * *     "Blue Whale".indexOf("Blue")    // returns 0 *     "Blue Whale".indexOf("Blute")   // returns -1 *     "Blue Whale".indexOf("Whale",0) // returns 5 *     "Blue Whale".indexOf("Whale",5) // returns 5 *     "Blue Whale".indexOf("",9)      // returns 9 *     "Blue Whale".indexOf("",10)     // returns 10 *     "Blue Whale".indexOf("",11)     // returns 10 * * The `indexOf` method is case sensitive. For example, the following expression returns -1: * *     "Blue Whale".indexOf("blue") * * Note that '0' doesn't evaluate to true and '-1' doesn't evaluate to false. Therefore, when checking if a specific string exists * within another string the correct way to check would be: * *     "Blue Whale".indexOf("Blue") != -1 // true *     "Blue Whale".indexOf("Bloe") != -1 // false * * The following example uses indexOf and lastIndexOf to locate values in the string "Brave new world". * *     var anyString="Brave new world" * *     document.write("<P>The index of the first w from the beginning is " + anyString.indexOf("w"))          // Displays 8 *     document.write("<P>The index of the first w from the end is " + anyString.lastIndexOf("w"))      // Displays 10 *     document.write("<P>The index of 'new' from the beginning is " + anyString.indexOf("new"))        // Displays 6 *     document.write("<P>The index of 'new' from the end is " + anyString.lastIndexOf("new"))    // Displays 6 * * The following example defines two string variables. The variables contain the same string except that the second string contains * uppercase letters. The first `writeln` method displays 19. But because the `indexOf` method is case sensitive, the string * "cheddar" is not found in `myCapString`, so the second `writeln` method displays -1. * *     myString="brie, pepper jack, cheddar" *     myCapString="Brie, Pepper Jack, Cheddar" *     document.writeln('myString.indexOf("cheddar") is ' + myString.indexOf("cheddar")) *     document.writeln('<P>myCapString.indexOf("cheddar") is ' + myCapString.indexOf("cheddar")) * * The following example sets count to the number of occurrences of the letter x in the string str: * *     count = 0; *     pos = str.indexOf("x"); *     while ( pos != -1 ) { *         count++; *         pos = str.indexOf("x",pos+1); *     } * * @param {String} searchValue A string representing the value to search for. * @param {Number} fromIndex The location within the calling string to start the search from. It can be any integer between 0 and * the length of the string. The default value is 0. * @return {Number} Position of specified value or -1 if not found. */<span id='String-method-lastIndexOf'>/**</span> * @method lastIndexOf * Returns the index within the calling String object of the last occurrence of * the specified value, or -1 if not found. The calling string is searched * backward, starting at fromIndex. * * Characters in a string are indexed from left to right. The index of the first character is 0, and the index of the last character * is `stringName.length - 1`. * *     "canal".lastIndexOf("a")   // returns 3 *     "canal".lastIndexOf("a",2) // returns 1 *     "canal".lastIndexOf("a",0) // returns -1 *     "canal".lastIndexOf("x")   // returns -1 * * The `lastIndexOf` method is case sensitive. For example, the following expression returns -1: * *     "Blue Whale, Killer Whale".lastIndexOf("blue") * * The following example uses `indexOf` and `lastIndexOf` to locate values in the string "`Brave new world`". * *     var anyString="Brave new world" * *     // Displays 8 *     document.write("<P>The index of the first w from the beginning is " + *     anyString.indexOf("w")) *     // Displays 10 *     document.write("<P>The index of the first w from the end is " + *     anyString.lastIndexOf("w")) *     // Displays 6 *     document.write("<P>The index of 'new' from the beginning is " + *     anyString.indexOf("new")) *     // Displays 6 *     document.write("<P>The index of 'new' from the end is " + *     anyString.lastIndexOf("new")) * * @param {String} searchValue A string representing the value to search for. * @param {Number} fromIndex The location within the calling string to start the search from, indexed from left to right. It can * be any integer between 0 and the length of the string. The default value is the length of the string. * @return {Number} */<span id='String-method-localeCompare'>/**</span> * @method localeCompare * Returns a number indicating whether a reference string comes before or after or is the same as the * given string in sort order. * * Returns a number indicating whether a reference string comes before or after or is the same as the * given string in sort order. Returns -1 if the string occurs earlier in a sort than `compareString`, * returns 1 if the string occurs afterwards in such a sort, and returns 0 if they occur at the same * level. * * The following example demonstrates the different potential results for a string occurring before, * after, or at the same level as another: * *     alert('a'.localeCompare('b')); // -1 *     alert('b'.localeCompare('a')); // 1 *     alert('b'.localeCompare('b')); // 0 * * @param {String} compareString The string against which the referring string is comparing. * @return {Number} Returns -1 if the string occurs earlier in a sort than * compareString, returns 1 if the string occurs afterwards in such a sort, and * returns 0 if they occur at the same level. */<span id='String-method-match'>/**</span> * @method match * Used to match a regular expression against a string. * * If the regular expression does not include the `g` flag, returns the same result as `regexp.exec(string)`. * * If the regular expression includes the `g` flag, the method returns an Array containing all matches. If there were no matches, * the method returns `null`. * * The returned {@link Array} has an extra `input` property, which contains the regexp that generated it as a result. In addition, * it has an `index` property, which represents the zero-based index of the match in the string. * * In the following example, `match` is used to find "Chapter" followed by 1 or more numeric characters followed by a decimal point * and numeric character 0 or more times. The regular expression includes the `i` flag so that case will be ignored. * *     str = "For more information, see Chapter 3.4.5.1"; *     re = /(chapter \d+(\.\d)*)/i; *     found = str.match(re); *     document.write(found); * * This returns the array containing Chapter 3.4.5.1,Chapter 3.4.5.1,.1 * * "`Chapter 3.4.5.1`" is the first match and the first value remembered from `(Chapter \d+(\.\d)*)`. * * "`.1`" is the second value remembered from `(\.\d)`. * * The following example demonstrates the use of the global and ignore case flags with `match`. All letters A through E and a * through e are returned, each its own element in the array * *     var str = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; *     var regexp = /[A-E]/gi; *     var matches_array = str.match(regexp); *     document.write(matches_array); * * `matches_array` now equals `['A', 'B', 'C', 'D', 'E', 'a', 'b', 'c', 'd', 'e']`. * * @param {RegExp} regexp A {@link RegExp} object. If a non-RegExp object `obj` is passed, it is * implicitly converted to a RegExp by using `new RegExp(obj)`. * @return {Array} Contains results of the match (if any). */<span id='String-method-replace'>/**</span> * @method replace * Used to find a match between a regular expression and a string, and to replace the matched substring * with a new substring. * * This method does not change the `String` object it is called on. It simply returns a new string. * * To perform a global search and replace, either include the `g` flag in the regular expression or if * the first parameter is a string, include `g` in the flags parameter. * * The replacement string can include the following special replacement patterns: * * | Pattern       | Inserts * |:--------------|:-------------------------------------------------------------------------------------- * | `$$`          | Inserts a `$`. * | `$&`          | Inserts the matched substring. * | `$``          | Inserts the portion of the string that precedes the matched substring. * | `$'`          | Inserts the portion of the string that follows the matched substring. * | `$n` or `$nn` | Where `n` or `nn` are decimal digits, inserts the _n_th parenthesized submatch string, provided the first * |               | argument was a `RegExp` object. * * You can specify a function as the second parameter. In this case, the function will be invoked after the match has been * performed. The function's result (return value) will be used as the replacement string. (Note: the above-mentioned special * replacement patterns do not apply in this case.) Note that the function will be invoked multiple times for each full match to be * replaced if the regular expression in the first parameter is global. * * The arguments to the function are as follows: * * | Possible Name | Supplied Value * |:--------------|:-------------------------------------------------------------------------------------- * | `str`         | The matched substring. (Corresponds to `$&` above.) * | `p1, p2, ...` | The _n_th parenthesized submatch string, provided the first argument to replace was a `RegExp` object. * |               | (Correspond to $1, $2, etc. above.) * | `offset`      | The offset of the matched substring within the total string being examined. (For example, if the total string * |               | was "`abcd`", and the matched substring was "`bc`", then this argument will be 1.) * | `s`           | The total string being examined. * * (The exact number of arguments will depend on whether the first argument was a `RegExp` object and, if so, how many parenthesized * submatches it specifies.) * * The following example will set `newString` to "`XXzzzz - XX , zzzz`": * *     function replacer(str, p1, p2, offset, s) *     { *         return str + " - " + p1 + " , " + p2; *     } *     var newString = "XXzzzz".replace(/(X*)(z*)/, replacer); * * In the following example, the regular expression includes the global and ignore case flags which permits replace to replace each * occurrence of 'apples' in the string with 'oranges'. * *     var re = /apples/gi; *     var str = "Apples are round, and apples are juicy."; *     var newstr = str.replace(re, "oranges"); *     print(newstr); * * In this version, a string is used as the first parameter and the global and ignore case flags are specified in the flags * parameter. * *     var str = "Apples are round, and apples are juicy."; *     var newstr = str.replace("apples", "oranges", "gi"); *     print(newstr); * * Both of these examples print "oranges are round, and oranges are juicy." * * In the following example, the regular expression is defined in replace and includes the ignore case flag. * *     var str = "Twas the night before Xmas..."; *     var newstr = str.replace(/xmas/i, "Christmas"); *     print(newstr); * * This prints "Twas the night before Christmas..." * * The following script switches the words in the string. For the replacement text, the script uses the $1 and $2 replacement * patterns. * *     var re = /(\w+)\s(\w+)/; *     var str = "John Smith"; *     var newstr = str.replace(re, "$2, $1"); *     print(newstr); * * This prints "Smith, John". * * In this example, all occurrences of capital letters in the string are converted to lower case, and a hyphen is inserted just * before the match location. The important thing here is that additional operations are needed on the matched item before it is * given back as a replacement. * * The replacement function accepts the matched snippet as its parameter, and uses it to transform the case and concatenate the * hyphen before returning. * *     function styleHyphenFormat(propertyName) *     { *         function upperToHyphenLower(match) *         { *             return '-' + match.toLowerCase(); *         } *         return propertyName.replace(/[A-Z]/, upperToHyphenLower); *     } * * Given `styleHyphenFormat('borderTop')`, this returns 'border-top'. * * Because we want to further transform the _result_ of the match before the final substitution is made, we must use a function. * This forces the evaluation of the match prior to the `toLowerCase()` method. If we had tried to do this using the match without a *  function, the `toLowerCase()` would have no effect. * *     var newString = propertyName.replace(/[A-Z]/, '-' + '$&'.toLowerCase());  // won't work * * This is because `'$&'.toLowerCase()` would be evaluated first as a string literal (resulting in the same `'$&'`) before using the * characters as a pattern. * * The following example replaces a Fahrenheit degree with its equivalent Celsius degree. The Fahrenheit degree should be a number * ending with F. The function returns the Celsius number ending with C. For example, if the input number is 212F, the function *  returns 100C. If the number is 0F, the function returns -17.77777777777778C. * * The regular expression `test` checks for any number that ends with F. The number of Fahrenheit degree is accessible to the * function through its second parameter, `p1`. The function sets the Celsius number based on the Fahrenheit degree passed in a * string to the `f2c` function. `f2c` then returns the Celsius number. This function approximates Perl's `s///e` flag. * *     function f2c(x) *     { *         function convert(str, p1, offset, s) *         { *             return ((p1-32) * 5/9) + "C"; *         } *         var s = String(x); *         var test = /(\d+(?:\.\d*)?)F\b/g; *         return s.replace(test, convert); *     } * * @param {String/RegExp} pattern Either a string or regular expression pattern to search for. * * @param {String/Function} replacement Either string or function: * * - The String to replace the `pattern` with. Number of special replacement patterns are supported; *   see the "Specifying a string as a parameter" section above. * - A function to be invoked to create the replacement. *   The arguments supplied to this function are described in the "Specifying a function as a parameter" *   section above. * * @return {String} String of matched replaced items. */<span id='String-method-search'>/**</span> * @method search * Executes the search for a match between a regular expression and a specified string. * * If successful, search returns the index of the regular expression inside the string. Otherwise, it * returns -1. * * When you want to know whether a pattern is found in a string use search (similar to the regular * expression `test` method); for more information (but slower execution) use `match` (similar to the * regular expression `exec` method). * * The following example prints a message which depends on the success of the test. * *     function testinput(re, str){ *         if (str.search(re) != -1) *             midstring = " contains "; *         else *             midstring = " does not contain "; *         document.write (str + midstring + re); *     } * * @param {RegExp} regexp A regular expression object. If a non-RegExp object obj is passed, it is * implicitly converted to a RegExp by using `new RegExp(obj)`. * @return {Number} If successful, search returns the index of the regular * expression inside the string. Otherwise, it returns -1. */<span id='String-method-slice'>/**</span> * @method slice * Extracts a section of a string and returns a new string. * * `slice` extracts the text from one string and returns a new string. Changes to the text in one * string do not affect the other string. * * `slice` extracts up to but not including `endSlice`. `string.slice(1,4)` extracts the second * character through the fourth character (characters indexed 1, 2, and 3). * * As a negative index, `endSlice` indicates an offset from the end of the string. `string.slice(2,-1)` * extracts the third character through the second to last character in the string. * * The following example uses slice to create a new string. * *     // assumes a print function is defined *     var str1 = "The morning is upon us."; *     var str2 = str1.slice(4, -2); *     print(str2); * * This writes: * *     morning is upon u * * @param {Number} beginSlice The zero-based index at which to begin extraction. * @param {Number} endSlice The zero-based index at which to end extraction. If omitted, `slice` * extracts to the end of the string. * @return {String} All characters from specified start up to (but excluding) * end. */<span id='String-method-split'>/**</span> * @method split * Splits a `String` object into an array of strings by separating the string into substrings. * * The `split` method returns the new array. * * When found, `separator` is removed from the string and the substrings are returned in an array. If * `separator` is omitted, the array contains one element consisting of the entire string. * * If `separator` is a regular expression that contains capturing parentheses, then each time separator * is matched the results (including any undefined results) of the capturing parentheses are spliced * into the output array. However, not all browsers support this capability. * * Note: When the string is empty, `split` returns an array containing one empty string, rather than an * empty array. * * The following example defines a function that splits a string into an array of strings using the * specified separator. After splitting the string, the function displays messages indicating the * original string (before the split), the separator used, the number of elements in the array, and the * individual array elements. * *     function splitString(stringToSplit,separator) *     { *         var arrayOfStrings = stringToSplit.split(separator); *         print('The original string is: "' + stringToSplit + '"'); *         print('The separator is: "' + separator + '"'); *         print("The array has " + arrayOfStrings.length + " elements: "); * *         for (var i=0; i < arrayOfStrings.length; i++) *             print(arrayOfStrings[i] + " / "); *     } * *     var tempestString = "Oh brave new world that has such people in it."; *     var monthString = "Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec"; * *     var space = " "; *     var comma = ","; * *     splitString(tempestString, space); *     splitString(tempestString); *     splitString(monthString, comma); * * This example produces the following output: * *     The original string is: "Oh brave new world that has such people in it." *     The separator is: " " *     The array has 10 elements: Oh / brave / new / world / that / has / such / people / in / it. / * *     The original string is: "Oh brave new world that has such people in it." *     The separator is: "undefined" *     The array has 1 elements: Oh brave new world that has such people in it. / * * The original string is: "Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec" * The separator is: "," * The array has 12 elements: Jan / Feb / Mar / Apr / May / Jun / Jul / Aug / Sep / Oct / Nov / Dec / * * In the following example, `split` looks for 0 or more spaces followed by a semicolon followed by 0 * or more spaces and, when found, removes the spaces from the string. nameList is the array returned * as a result of split. * *     var names = "Harry Trump ;Fred Barney; Helen Rigby ; Bill Abel ;Chris Hand "; *     print(names); *     var re = /\s*;\s*\/; *     var nameList = names.split(re); *     print(nameList); * * This prints two lines; the first line prints the original string, and the second line prints the * resulting array. * *     Harry Trump ;Fred Barney; Helen Rigby ; Bill Abel ;Chris Hand *     Harry Trump,Fred Barney,Helen Rigby,Bill Abel,Chris Hand * * In the following example, split looks for 0 or more spaces in a string and returns the first 3 * splits that it finds. * *     var myString = "Hello World. How are you doing?"; *     var splits = myString.split(" ", 3); *     print(splits); * * This script displays the following: * *     Hello,World.,How * * If `separator` contains capturing parentheses, matched results are returned in the array. * *     var myString = "Hello 1 word. Sentence number 2."; *     var splits = myString.split(/(\d)/); *     print(splits); * * This script displays the following: * *     Hello ,1, word. Sentence number ,2, . * * @param {String} seperator Specifies the character to use for separating the string. The separator is treated as a string or a * regular expression. If separator is omitted, the array returned contains one element consisting of the entire string. * @param {Number} limit Integer specifying a limit on the number of splits to be found.  The split method still splits on every * match of separator, but it truncates the returned array to at most limit elements. * @return {Array} Substrings are returned in an array. */<span id='String-method-substr'>/**</span> * @method substr * Returns the characters in a string beginning at the specified location through the specified number * of characters. * * `start` is a character index. The index of the first character is 0, and the index of the last * character is 1 less than the length of the string. `substr` begins extracting characters at start * and collects length characters (unless it reaches the end of the string first, in which case it will * return fewer). * * If `start` is positive and is greater than or equal to the length of the string, `substr` returns an * empty string. * * If `start` is negative, `substr` uses it as a character index from the end of the string. If start * is negative and abs(start) is larger than the length of the string, `substr` uses 0 as the start * index. Note: the described handling of negative values of the start argument is not supported by * Microsoft JScript. * * If length is 0 or negative, `substr` returns an empty string. If length is omitted, `substr` * extracts characters to the end of the string. * * Consider the following script: * *     // assumes a print function is defined *     var str = "abcdefghij"; *     print("(1,2): "    + str.substr(1,2)); *     print("(-3,2): "   + str.substr(-3,2)); *     print("(-3): "     + str.substr(-3)); *     print("(1): "      + str.substr(1)); *     print("(-20, 2): " + str.substr(-20,2)); *     print("(20, 2): "  + str.substr(20,2)); * * This script displays: * *     (1,2): bc *     (-3,2): hi *     (-3): hij *     (1): bcdefghij *     (-20, 2): ab *     (20, 2): * * @param {Number} start Location at which to begin extracting characters. * @param {Number} length The number of characters to extract. * @return {String} Modified string. */<span id='String-method-substring'>/**</span> * @method substring * Returns the characters in a string between two indexes into the string. * * substring extracts characters from indexA up to but not including indexB. In particular: * *   If `indexA` equals `indexB`, `substring` returns an empty string. * *   If `indexB` is omitted, substring extracts characters to the end of the string. * *   If either argument is less than 0 or is `NaN`, it is treated as if it were 0. * *   If either argument is greater than `stringName.length`, it is treated as if it were * `stringName.length`. * * If `indexA` is larger than `indexB`, then the effect of substring is as if the two arguments were * swapped; for example, `str.substring(1, 0) == str.substring(0, 1)`. * * The following example uses substring to display characters from the string "Sencha": * *     // assumes a print function is defined *     var anyString = "Sencha"; * *     // Displays "Sen" *     print(anyString.substring(0,3)); *     print(anyString.substring(3,0)); * *     // Displays "cha" *     print(anyString.substring(3,6)); *     print(anyString.substring(6,3)); * *     // Displays "Sencha" *     print(anyString.substring(0,6)); *     print(anyString.substring(0,10)); * * The following example replaces a substring within a string. It will replace both individual * characters and `substrings`. The function call at the end of the example changes the string "Brave * New World" into "Brave New Web". * *     function replaceString(oldS, newS, fullS) { *         // Replaces oldS with newS in the string fullS *         for (var i = 0; i < fullS.length; i++) { *             if (fullS.substring(i, i + oldS.length) == oldS) { *                 fullS = fullS.substring(0, i) + newS + fullS.substring(i + oldS.length, * fullS.length); *             } *         } *         return fullS; *     } * *     replaceString("World", "Web", "Brave New World"); * * @param {Number} indexA An integer between 0 and one less than the length of the string. * @param {Number} indexB (optional) An integer between 0 and the length of the string. * @return {String} Returns the characters in a string between two indexes into the string. */<span id='String-method-toLocaleLowerCase'>/**</span> * @method toLocaleLowerCase * The characters within a string are converted to lower case while respecting the current locale. For * most languages, this will return the same as `toLowerCase`. * * The `toLocaleLowerCase` method returns the value of the string converted to lower case according to * any locale-specific case mappings. `toLocaleLowerCase` does not affect the value of the string * itself. In most cases, this will produce the same result as `toLowerCase()`, but for some locales, * such as Turkish, whose case mappings do not follow the default case mappings in Unicode, there may * be a different result. * * The following example displays the string "sencha": * *     var upperText="sencha"; *     document.write(upperText.toLocaleLowerCase()); * * @return {String} Returns value of the string in lowercase. */<span id='String-method-toLocaleUpperCase'>/**</span> * @method toLocaleUpperCase * The characters within a string are converted to upper case while respecting the current locale. For * most languages, this will return the same as `toUpperCase`. * * The `toLocaleUpperCase` method returns the value of the string converted to upper case according to * any locale-specific case mappings. `toLocaleUpperCase` does not affect the value of the string * itself. In most cases, this will produce the same result as `toUpperCase()`, but for some locales, * such as Turkish, whose case mappings do not follow the default case mappings in Unicode, there may * be a different result. * * The following example displays the string "SENCHA": * *     var lowerText="sencha"; *     document.write(lowerText.toLocaleUpperCase()); * * @return {String} Returns value of the string in uppercase. */<span id='String-method-toLowerCase'>/**</span> * @method toLowerCase * Returns the calling string value converted to lower case. * * The `toLowerCase` method returns the value of the string converted to lowercase. `toLowerCase` does * not affect the value of the string itself. * * The following example displays the lowercase string "sencha": * *     var upperText="SENCHA"; *     document.write(upperText.toLowerCase()); * * @return {String} Returns value of the string in lowercase. */<span id='String-method-toString'>/**</span> * @method toString * Returns a string representing the specified object. Overrides the `Object.toString` method. * * The `String` object overrides the `toString` method of the `Object` object; it does not inherit * `Object.toString`. For `String` objects, the `toString` method returns a string representation of * the object. * * The following example displays the string value of a String object: * *     x = new String("Hello world"); *     alert(x.toString())      // Displays "Hello world" * * @return {String} A string representation of the object. */<span id='String-method-toUpperCase'>/**</span> * @method toUpperCase * Returns the calling string value converted to uppercase. * * The `toUpperCase` method returns the value of the string converted to uppercase. `toUpperCase` does * not affect the value of the string itself. * * The following example displays the string "SENCHA": *     var lowerText="sencha"; *     document.write(lowerText.toUpperCase()); * * @return {String} Returns value of the string in uppercase. */<span id='String-method-valueOf'>/**</span> * @method valueOf * Returns the primitive value of the specified object. Overrides the `Object.valueOf` method. * * The `valueOf` method of String returns the primitive value of a `String` object as a string data * type. This value is equivalent to `String.toString`. * * This method is usually called internally by JavaScript and not explicitly in code. * *     x = new String("Hello world"); *     alert(x.valueOf())          // Displays "Hello world" * * @return {String} Returns value of string. */</pre></body></html>
 |