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All Rights Reserved Printed in the United States of America. 00 99 98 5 4 3 2 1 Netscape Communications Corporation, 501 East Middlefield Road, Mountain View, CA 94043 New Features in this Release JavaScript version 1.2 provides the following new features and enhancements: • Changes to the Array object. • Array objects can be created using literal notation. • When the <SCRIPT> tag includes LANGUAGE="JavaScript1.2", array(1) creates a new array with a[0]=1. • When created as the result of a match between a regular expression and a string, arrays have new properties that provide information about the match. • concat joins two arrays and returns a new array. • pop removes the last element from an array and returns that element. • push adds one or more elements to the end of an array and returns that last element added. • shift removes the first element from an array and returns that element • unshift adds one or more elements to the front of an array and returns the new length of the array. • slice extracts a section from an array and returns a new array • splice adds and/or removes elements from an array and returns the removed elements. • sort now works on all platforms. It no longer converts undefined elements to null; instead, it sorts them to the high end of the array. 3 • Changes to the Function object. • Nested functions. You can nest functions within functions. (That is, JavaScript now supports lambda expressions and lexical closures.) See Function. • New function property arity. The arity property indicates the number of arguments expected by a function. • New arguments property. The arguments.callee property provides information about the invoked function. • New Lock class. The Lock class allows safe sharing of information with multiple incoming requests. • Changes to the Number object. Number now produces NaN rather than an error if x is a string that does not contain a well-formed numeric literal. • New RegExp object for regular expressions. Regular expressions are patterns used to match character combinations in strings. You create a regular expression as an object that has methods used to execute a match against a string. You can also pass the regular expression as an argument to the String methods match, replace, search, and split. The RegExp object has properties most of which are set when a match is successful, such as lastMatch which specifies the last successful match. The Array object has new properties that provide information about a successful match such as input which specifies the original input string against which the match was executed. See RegExp for information. • New SendMail class. The SendMail class lets you generate email from JavaScript. • New or changed String methods. • charCodeAt returns a number specifying the ISO-Latin-1 codeset value of the character at the specified index in a string object. • concat combines the text of two strings and returns a new string. • fromCharCode constructs a string from a specified sequence of numbers that are ISO-Latin-1 codeset values. • match executes a search for a match between a string and a regular expression. 4 Server-Side JavaScript Reference • replace executes a search for a match between a string and a regular expression, and replaces the matched substring with a new substring. • search tests for a match between a string and a regular expression. • slice extracts a section of an string and returns a new string. • split includes several new features and changes. It can take a regular expression argument, as well as a fixed string, by which to split the object string. It can take a limit count so that it won't include trailing empty elements in the resulting array. If you specify LANGUAGE="JavaScript1.2" in the <SCRIPT> tag, string.split(" ") splits on any run of one or more white space characters including spaces, tabs, line feeds, and carriage returns. • substr returns the characters in a string collecting the specified number of characters beginning with a specified location in the string. • substring if you specify LANGUAGE="JavaScript1.2" in the <SCRIPT> tag, this method no longer swaps index numbers when the first index is greater than the second. • New top-level functions Number and String. The Number function converts an object to a number. The String function converts an object to a string. • Changes to methods of all objects. • eval is no longer a method of individual objects; it is available only as a top-level function. • toString converts an object or array to a literal. For this behavior, LANGUAGE="JavaScript1.2" must be specified in the <SCRIPT> tag. • watch is a new method of all objects. It watches for a property to be assigned a value and runs a function when that occurs. • unwatch is a new method of all objects. It removes a watchpoint set with the watch method. 5 • New or changed operators. • The new delete operator deletes an object, an object’s property, or an element at a specified index in an array. See “delete” on page 395. •If the <SCRIPT> tag uses LANGUAGE=JavaScript1.2, the equality operators == and != do not attempt to convert operands from one type to another, and always compare identity of like-typed operands. See “Comparison Operators” on page 385. • New or changed statements. • The break and continue statements can now be used with the new labeled statement. • do...while repeats a loop until the test condition evaluates to false. • export allows a signed script to provide functions to other signed or unsigned scripts. • import allows a script to import functions from a signed script which has exported the information. • label allows the program to break outside nested loops or to continue a loop outside the current loop. • switch allows the program to test several conditions easily. See the Server-Side JavaScript Guide for information on additional features. 6 Server-Side JavaScript Reference Contents New Features in this Release .......................................................................3 About this Book ..............................................................................................13 New Features in this Release ..............................................................................13 What You Should Already Know .......................................................................13 JavaScript Versions ..............................................................................................14 Where to Find JavaScript Information ................................................................15 Document Conventions .......................................................................................16 Part 1 Object Reference Chapter 1 Objects, Methods, and Properties ......................................21 Array .....................................................................................................................22 blob ......................................................................................................................43 Boolean ................................................................................................................48