C Program Operator Precedence and Associativity

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The operators at the top of this list are evaluated first this is called as precedence of operator. Operators within a group have the same precedence. All operators have left-to-right associativity unless otherwise noted.
When an expression contains multiple operators, the precedence of the operators controls the order in which the individual operators are evaluated. For example, the expression x + y * z is evaluated as x + (y * z) because the * operator has higher precedence than the binary + operator. The precedence of an operator is established by the definition of its associated grammar production. For example, an additive-expression consists of a sequence of multiplicative-expressions separated by + or - operators, thus giving the + and - operators lower precedence than the *, /, and % operators.

This page lists C operators in order of precedence (highest to lowest). Their associativityindicates in what order operators of equal precedence in an expression are applied.

Operator

Description

Associativity

()
[]
.
->
++  --
Parentheses (function call) (see Note 1)
Brackets (array subscript)
Member selection via object name
Member selection via pointer
Postfix increment/decrement (see Note 2)

left-to-right

++  --
+  -
!  ~
(type)
*
&
sizeof
 
 
Prefix increment/decrement
Unary plus/minus
Logical negation/bitwise complement
Cast (change type)
Dereference
Address
Determine size in bytes
right-to-left
*  /  % Multiplication/division/modulus left-to-right
+  - Addition/subtraction left-to-right
<<  >> Bitwise shift left, Bitwise shift right left-to-right
<  <=
>  >=
Relational less than/less than or equal to
Relational greater than/greater than or equal to
left-to-right
==  != Relational is equal to/is not equal to left-to-right
& Bitwise AND left-to-right
^ Bitwise exclusive OR left-to-right
| Bitwise inclusive OR left-to-right
&& Logical AND left-to-right
|| Logical OR left-to-right
?: Ternary conditional right-to-left
=
+=  -=
*=  /=
%=  &=
^=  |=
<<=  >>=
Assignment
Addition/subtraction assignment
Multiplication/division assignment
Modulus/bitwise AND assignment
Bitwise exclusive/inclusive OR assignment
Bitwise shift left/right assignment
right-to-left

,

Comma (separate expressions) left-to-right
Note 1:
Parentheses are also used to group sub-expressions to force a different precedence; such parenthetical expressions can be nested and are evaluated from inner to outer.
Note 2:
Postfix increment/decrement have high precedence, but the actual increment or decrement of the operand is delayed (to be accomplished sometime before the statement completes execution). So in the statement y = x * z++; the current value of z is used to evaluate the expression (i.e., z++ evaluates to z) and z only incremented after all else is done.

When an operand occurs between two operators with the same precedence, the associativity of the operators controls the order in which the operations are performed:

* Except for the assignment operators, all binary operators are left-associative, meaning that operations are performed from left to right. For example, x + y + z is evaluated as (x + y) + z.
* The assignment operators and the conditional operator (?:) are right-associative, meaning that operations are performed from right to left. For example, x = y = z is evaluated as x = (y = z).

Precedence and associativity can be controlled using parentheses. For example, x + y * z first multiplies y by z and then adds the result to x, but (x + y) * z first adds x and y and then multiplies the result by z.

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