Operator Precedence

The following tables show the order in which operators are evaluated. Please note the following.

The order in which the operands are evaluated is not specified in the ANSII standard.
For readability you should not rely on these rules! Put everything in brackets so you intension is clear to the compiler and other programmers.
It is important to note that there is no specified precedence for the operation of changing a variable into a value. For example, consider the following code:
```
 float x, result;
 x = 1;
 result = x / ++x; 
```
The value of result is not guaranteed to be consistent across different compilers, because it is not clear whether the computer should change the variable x before using it. The bottom line is that you should not use the same variable multiple times in a single expression when using operators with side effects.

o Summary table.
o Table in detail.
o Operators listed by type.

Summary precedence table.

All operators on the same line have the same precedence. The first line has the highest precedence.

() [] -> .

! ~ ++ -- + - * & sizeof

* / %

+ -

<< >>

< <= >= >

== !=

= += -= *= /= %= &= ^= |= <<= >>=

Lary Huang has told me that the postfix unary -- and postfix unary ++ have a higher precedence than the prefix unary -- and prefix unary ++.

Detailed precedence table.

All operators in the same 'block' have the same precedence. The first block has the highest precedence.

Group Operator Description Example

Membership.

() Function call
/Grouping count = function(4,3);
(a + b) / 4;

[] Array value = array[5] + increment;

-> Structure pointer ptr->age = 34;

. Structure member obj.age = 34;

:: Scoping Class::age = 2;

++ Post - Increment for( i = 0; i < 10; i++ ) ...

Post - Decrement for( i = 10; i > 0; i-- ) ...

Unary.

! Logical NOT if( !done ) ...

~ Bitwise complement flags = ~flags;

++ Pre-Increment for( i = 0; i < 10; ++i ) ...

-- Pre-Decrement for( i = 10; i > 0; --i ) ...

+ Unary plus int i = +1;

- Unary Minus int i = -1;

* Dereference, Pointer to data data = *ptr;

& Address of a variable address = &obj;

sizeof size in bytes int size = sizeof(floatNum);

(type) type cast int i = (int) floatNum;

selector

->* Member pointer selector ptr->*var = 24;

.* Member pointer selector obj.*var = 24;

Binary.

* Multiply. int i = 2 * 4;

/ Divide. float f = 10 / 3;

% Modulo. int rem = 4 % 3;

Binary term

+ Addition int i = 2 + 3;

- Subtraction. int i = 5 - 1;

Bitwise Shift

<< Bitwise shift left. int flags = 33 << 1;

>> Bitwise shift Right. int flags = 33 >> 1;

Relational.

< Less than. if( i < 42 ) ...

> Greater than. if( i > 42 ) ...

<= Less than or equal too. if( i <= 42 ) ...

>= Greater than or equal too. if( i >= 42 ) ...

Equality

== Equal too. if( i == 42 ) ...

!= Not equal too. if( i != 42 ) ...

Bitwise AND

& bitwise AND flags = flags & 42;

Bitwise XOR

^ bitwise Excusive OR flags = flags ^ 42;

Bitwise OR

| bitwise OR flags = flags | 42;

Logical.

&& Logical AND if( conditionA && conditionB ) ...

Logical.

|| Logical OR if( conditionA || conditionB ) ...

Conditional

? : Conditional construct. int i = (a > b) ? a : b;

Assignment

= Equals int a = b;

+= assignment a += 3;

-= assignment b -= 4;

*= assignment a *= 5;

/= assignment a /= 2;

%= assignment a %= 3;

&= assignment flags &= new_flags;

^= assignment flags ^= new_flags;

|= assignment flags ^= new_flags;

<<= assignment flags <<= 2;

>>= assignment flags >>= 2;

Series

, Comma for( i = 0, j = 0; i < 10; i++, j++ ) ...

Operator Precedence

Summary precedence table.

Detailed precedence table.

See also: