The precedence of PHP operators (high to low)

Operator(s) Type
() Parentheses
++ -- Increment/decrement
! Logical
* / % Arithmetic
+ - . Arithmetic and string
<< >> Bitwise
< <= > >= <> Comparison
== != === !== Comparison
& Bitwise (and references)
^ Bitwise
| Bitwise
&& Logical
|| Logical
? : Ternary
= += -= *= /= .= %= &= != ^= <<= >>= Assignment
and Logical
xor Logical
or Logical

Operator associativity

Operator Description Associativity
CLONE NEW Create a new object None
< <= >= == != === !== <> Comparison None
! Logical NOT Right
~ Bitwise NOT Right
++ -- Increment and decrement Right
(int) Cast to an integer Right
(double) (float) (real) Cast to a floating-point number Right
(string) Cast to a string Right
(array) Cast to an array Right
(object) Cast to an object Right
@ Inhibit error reporting Right
= += -= *= /= Assignment Right
.= %= &= |= ^= <<= >>= Assignment Right
+ Addition and unary plus Left
- Subtraction and negation Left
* Multiplication Left
/ Division Left
% Modulus Left
. String concatenation Left
<< >> & ^ | Bitwise Left
?: Ternary Left
|| && and or xor Logical Left
, Separator Left