# Var := expression

Evaluates an expression and stores the result in a variable.

    Var := expression

## Parameters

Var

  The name of the variable in which to store the result of expression.

Expression

  See expressions and the examples below for details.

## Remarks

The := operator is optimized so that it performs just as quickly as the = operator for simple cases such as the following:

    x := y  ; Same performance as x = %y%
    x := 5  ; Same performance as x = 5.
    x := "literal string"  ; Same performance as x = literal string.

The words `true` and `false` are built-in constants containing 1 and 0. They can be used to make a script more readable as in these examples:

    CaseSensitive := false
    ContinueSearch := true

It is possible to create a pseudo-array with this command and any others that accept an OutputVar. This is done by making OutputVar contain a reference to another variable, e.g. `Array%i% := Var/100 + 5`. See Arrays for more information.

## Related

Expressions, If (expression), Functions, SetEnv, EnvSet, EnvAdd, EnvSub, EnvMult, EnvDiv, If (legacy), Arrays

## Examples

#1

    Var := 3
    Var := "literal string"
    Var := Price * (1 - Discount/100)

    Finished := not Done or A_Index > 100
    if not Finished
    {
        FileAppend, %NewText%`n, %TargetFile%
        return
    }
    else
        ExitApp