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.
This feature is obsolete.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.
@set statement creates variables used with conditional compilation statements.
@set @varname = term
- Zero or more unary operators followed by a constant, conditional compilation variable, or parenthesized expression.
Numeric and Boolean variables are supported for conditional compilation. Strings are not. Variables created using
Examples of variable declarations look like this:
@set @myvar1 = 12 @set @myvar2 = (@myvar1 * 20) @set @myvar3 = @_jscript_version
The following operators are supported in parenthesized expressions:
* / %
<< >> >>>
< <= > >=
== != === !==
& ^ |
&& | |
If a variable is used before it has been defined, its value is
NaN can be checked for using the
@if (@newVar != @newVar) ...
This works because
NaN is the only value not equal to itself.
Supported in all versions of Internet Explorer, but not in Windows 8.x Store apps.