Non-standard
This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
Obsolete
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.
The @if
statement conditionally executes a group of statements, depending on the value of an expression.
Syntax
@if ( condition1 ) text1 [@elif ( condition2 ) text2] [@else text3] @end
Parameters
text1
Optional- Text to be parsed if
condition1
is true. text2
Optional- Text to be parsed if
condition1
is false andcondition2
is true. text3
Optional- Text to be parsed if both
condition1
andcondition2
are false.
Remarks
When you write an @if
statement, you do not have to place each clause on a separate line. You can use multiple @elif clauses. However, all @elif clauses must come before an @elseclause.
The @if
statement is typically used to determine which text among several options should be used for text output.
It is not common to use conditional compilation variables in scripts written for ASP or ASP.NET pages or command-line programs. This is because the capabilities of the compilers can be determined by using other methods.
When you write a script for a Web page, always add conditional compilation code in comments. This enables hosts that do not support conditional compilation to ignore it.
Example
The following example illustrates the use of the @if...@elif...@else...@end statement.
/*@cc_on @*/ /*@ document.write("JavaScript version: " + @_jscript_version + "."); document.write("<br />"); @if (@_win32) document.write("Running on a 32-bit version of Windows."); @elif (@_win16) document.write("Running on a 16-bit version of Windows."); @else document.write("Running on a different operating system."); @end @*/
Requirements
Supported in all versions of Internet Explorer, but not in Windows 8.x Store apps.