c++运算优先级列表

Precedence Operator Description Example Associativity 1 ()
[]
->
.
::
++
-- Grouping operator
Array access
Member access from a pointer
Member access from an object
Scoping operator
Post-increment
Post-decrement (a + b) / 4;
array[4] = 2;
ptr->age = 34;
obj.age = 34;
Class::age = 2;
for( i = 0; i < 10; i++ ) ...
for( i = 10; i > 0; i-- ) ... left to right 2 !
~
++
--
-
+
*
&
(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 3 ->*
.* Member pointer selector
Member pointer selector ptr->*var = 24;
obj.*var = 24; left to right 4 *
/
% Multiplication
Division
Modulus int i = 2 * 4;
float f = 10 / 3;
int rem = 4 % 3; left to right 5 +
- Addition
Subtraction int i = 2 + 3;
int i = 5 - 1; left to right 6 <<
>> Bitwise shift left
Bitwise shift right int flags = 33 << 1;
int flags = 33 >> 1; left to right 7 <
<=
>
>= 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 8 ==
!= Comparison equal-to
Comparison not-equal-to if( i == 42 ) ...
if( i != 42 ) ... left to right 9 & Bitwise AND flags = flags & 42; left to right 10 ^ Bitwise exclusive OR flags = flags ^ 42; left to right 11 | Bitwise inclusive (normal) OR flags = flags | 42; left to right 12 && Logical AND if( conditionA && conditionB ) ... left to right 13 || Logical OR if( conditionA || conditionB ) ... left to right 14 ? : Ternary conditional (if-then-else) int i = (a > b) ? a : b; right to left 15 =
+=
-=
*=
/=
%=
&=
^=
|=
<<=
>>= 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 16 , Sequential evaluation operator for( i = 0, j = 0; i < 10; i++, j++ ) ... left to right   记忆方法：--摘自《C语言程序设计实用问答》     -吕凤翥     吕     涛著   
    问题：如何记住运算符的15种优先级和结合性？   
    解答：C语言中运算符种类比较繁多，优先级有15种，结合性有两种。   
    如何记忆两种结合性和15种优先级？下面讲述一种记忆方法。   
    结合性有两种，一种是自左至右，另一种是自右至左，大部分运算符的结合性是自左至右，只有单目运算符、三目运算符的赋值运算符的结合性自右至左。   
    优先级有15种。记忆方法如下：   
    记住一个最高的：构造类型的元素或成员以及小括号。   
    记住一个最低的：逗号运算符。   
    剩余的是一、二、三、赋值。   
    意思是单目、双目、三目和赋值运算符。   
    在诸多运算符中，又分为：   
    算术、关系、逻辑。   
    两种位操作运算符中，移位运算符在算术运算符后边，逻辑位运算符在逻辑运算符的前面。再细分如下：   
    算术运算符分     *，/，%高于+，-。   
    关系运算符中，》，》=，《，〈=高于==，！=。   
    逻辑运算符中，除了逻辑求反（！）是单目外，逻辑与（&&）高于逻辑或（||）。   
    逻辑位运算符中，除了逻辑按位求反（~）外，按位与（&)高于按位半加（^)，高于按位或（|）。   
    这样就将15种优先级都记住了，再将记忆方法总结如下：   
    去掉一个最高的，去掉一个最低的，剩下的是一、二、三、赋值。双目运算符中，顺序为算术、关系和逻辑，移位和逻辑位插入其中。