PHP » Operators » -=

Syntax:
$var -= expression
var
A variable.
expression
A value to subtract from the variable.

Subtraction assignment operator.

Subtracts the right operand from the left operand.

Examples

Code:
<?php

$a = 5;
$a -= 5;
print $a;

?>
Output:
0
Explanation:

A variable is changed with an assignment operator.