Operators


Operator Precedence

The precedence of an operator specifies how "tightly" it binds two expressions together. The operator precedence is as follows:

Precedence Operator Mark Operators
High















Low
[ ( Parenthesis
++ -- ~ (int) (string) (bool) Types/Increment/Decrement
! Logical
* / % Arithmetic
+ - . Arithmetic
<< >> Bitwise
< <= > >= Comparison
== != === !== <> Comparison
& Bitwise
^ Bitwise
| Bitwise
&& Logical
|| Logical
? : Ternary
= += -= *= /= .= %= &= |= ^= <<= >>= Assignment

When operators which have the same priority are used repeatedly, calculation is started from the left. However, for the assignment, increment/decrement, cast and logical operator'!', the operation starts from the right.

<?php
    $var0 = 3 * 3 % 5;           // (3 * 3) % 5 = 4 (from left)

    $var1 = 1;
    $var2 = 2;
    $var1 = $var2 += 3;          // $var1 = ($var2 += 3), $var1, $var2 = 5 (from right)
?>