JavaScript tutorial:
@set statement 

The @set statement creates variables used with conditional compilation statements.

Syntax

@set @varname = term

The @set statement syntax has these parts:

Part	Description
varname	Valid JavaScript variable name. Must be preceded by an "@" character at all times.
term	Zero or more unary operators followed by a constant, conditional compilation variable, or parenthesized expression.

Return value

None

Example

Numeric and Boolean variables are supported for conditional compilation. Strings are not. Variables created using @set are generally used in conditional compilation statements, but can be used anywhere in JavaScript code.

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. NaN can be checked for using the @if statement:

@if (@newVar != @newVar)
...

This works because NaN is the only value not equal to itself.

See also: Conditional Compilation, Conditional Compilation Variables, @cc_on Statement, @if Statement