[转]C++操作符优先级

原地址:http://www.cppreference.com/operator_precedence.html

 

C++ Operator Precedence

The operators at the top of this list are evaluated first.

Precedence

Operator

Description

Example

Associativity

1

::

Scoping operator

Class::age = 2;

none

2

()
[]
->
.
++
--

Grouping operator
Array access
Member access from a pointer
Member access from an object
Post-increment
Post-decrement

(a + b) / 4;
array[4] = 2;
ptr->age = 34;
obj.age = 34;
for( i = 0; i < 10; i++ ) ...
for( i = 10; i > 0; i-- ) ...

left to right

3

!
~
++
--
-
+
*
&
(type)
sizeof

Logical negation
Bitwise complement
Pre-increment
Pre-decrement
Unary minus
Unary plus
Dereference
Address of
Cast to a given type
Return size in bytes

if( !done ) ...
flags = ~flags;
for( i = 0; i < 10; ++i ) ...
for( i = 10; i > 0; --i ) ...
int i = -1;
int i = +1;
data = *ptr;
address = &obj;
int i = (int) floatNum;
int size = sizeof(floatNum);

right to left

4

->*
.*

Member pointer selector
Member object selector

ptr->*var = 24;
obj.*var = 24;

left to right

5

*
/
%

Multiplication
Division
Modulus

int i = 2 * 4;
float f = 10 / 3;
int rem = 4 % 3;

left to right

6

+
-

Addition
Subtraction

int i = 2 + 3;
int i = 5 - 1;

left to right

7

<<
>>

Bitwise shift left
Bitwise shift right

int flags = 33 << 1;
int flags = 33 >> 1;

left to right

8

<
<=
>
>=

Comparison less-than
Comparison less-than-or-equal-to
Comparison greater-than
Comparison geater-than-or-equal-to

if( i < 42 ) ...
if( i <= 42 ) ...
if( i > 42 ) ...
if( i >= 42 ) ...

left to right

9

==
!=

Comparison equal-to
Comparison not-equal-to

if( i == 42 ) ...
if( i != 42 ) ...

left to right

10

&

Bitwise AND

flags = flags & 42;

left to right

11

^

Bitwise exclusive OR

flags = flags ^ 42;

left to right

12

|

Bitwise inclusive (normal) OR

flags = flags | 42;

left to right

13

&&

Logical AND

if( conditionA && conditionB ) ...

left to right

14

||

Logical OR

if( conditionA || conditionB ) ...

left to right

15

? :

Ternary conditional (if-then-else)

int i = (a > b) ? a : b;

right to left

16

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

Assignment operator
Increment and assign
Decrement and assign
Multiply and assign
Divide and assign
Modulo and assign
Bitwise AND and assign
Bitwise exclusive OR and assign
Bitwise inclusive (normal) OR and assign
Bitwise shift left and assign
Bitwise shift right and assign

int a = b;
a += 3;
b -= 4;
a *= 5;
a /= 2;
a %= 3;
flags &= new_flags;
flags ^= new_flags;
flags |= new_flags;
flags <<= 2;
flags >>= 2;

right to left

17

,

Sequential evaluation operator

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

left to right

 

posted @ 2010-12-30 17:35  网络小虫  阅读(262)  评论(0编辑  收藏  举报