Microsoft® JScript Conditional Compilation |
Language Reference Version 3 |
Allows the use of new JScript language features without sacrificing compatibility with browsers that don't support them.
Conditional compilation is activated by using the @cc_on statement, or using an @if or @set statement outside of a comment. Some typical uses for conditional compilation are using new features in JScript, embedding debugging support into a script, and tracing code execution.This example uses special comment delimiters that are only used if conditional compilation is activated by the @cc_on statement. Scripting engines that do not understand conditional compilation only see the alert statement informing of the need for a new scripting engine.It is strongly recommended that conditional compilation code be placed in comments:
//@cc_on /*@if @_jscript_version == 3 alert("JScript version 3") @else @*/ alert("You need a more recent script engine.") //@end