Short Assignations

In addition to the basic assignment operator, there are combined operators for all of the binary arithmetic, array union and string operators that allow to use a value in an expression and then set its value to the result of that expression.

<?php

    // incrementing $a by one
    $a = $a + 1;

    // short assignement for the above syntax
    $a += 1;

?>

Documentation

See also PHP — P22: Shorthand Operators.

Related : Assignations, Assignations, Bitwise Operators, Iffectation