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.

- Example of Operator Precedence

```
<?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)
?>
```