優先級 |
運算符 |
名稱或含義 |
使用形式 |
結合方向 |
說明 |
1 |
[] |
數組下標 |
數組名[常量表達式] |
左到右 |
|
() |
圓括號 |
(表達式)/函數名(形參表) |
|||
. |
成員選擇(對象) |
對象.成員名 |
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-> |
成員選擇(指針) |
對象指針->成員名 |
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2 |
- |
負號運算符 |
-表達式 |
右到左 |
單目運算符 |
(類型) |
強制類型轉換 |
(數據類型)表達式 |
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++ |
自增運算符 |
++變量名/變量名++ |
單目運算符 |
||
-- |
自減運算符 |
--變量名/變量名-- |
單目運算符 |
||
* |
取值運算符 |
*指針變量 |
單目運算符 |
||
& |
取地址運算符 |
&變量名 |
單目運算符 |
||
! |
邏輯非運算符 |
!表達式 |
單目運算符 |
||
~ |
按位取反運算符 |
~表達式 |
單目運算符 |
||
sizeof |
長度運算符 |
sizeof(表達式) |
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3 |
/ |
除 |
表達式/表達式 |
左到右 |
雙目運算符 |
* |
乘 |
表達式*表達式 |
雙目運算符 |
||
% |
餘數(取模) |
整型表達式/整型表達式 |
雙目運算符 |
||
4 |
+ |
加 |
表達式+表達式 |
左到右 |
雙目運算符 |
- |
減 |
表達式-表達式 |
雙目運算符 |
||
5 |
<< |
左移 |
變量<<表達式 |
左到右 |
雙目運算符 |
>> |
右移 |
變量>>表達式 |
雙目運算符 |
||
6 |
> |
大於 |
表達式>表達式 |
左到右 |
雙目運算符 |
>= |
大於等於 |
表達式>=表達式 |
雙目運算符 |
||
< |
小於 |
表達式<表達式 |
雙目運算符 |
||
<= |
小於等於 |
表達式<=表達式 |
雙目運算符 |
||
7 |
== |
等於 |
表達式==表達式 |
左到右 |
雙目運算符 |
!= |
不等於 |
表達式!= 表達式 |
雙目運算符 |
||
8 |
& |
按位與 |
表達式&表達式 |
左到右 |
雙目運算符 |
9 |
^ |
按位異或 |
表達式^表達式 |
左到右 |
雙目運算符 |
10 |
| |
按位或 |
表達式|表達式 |
左到右 |
雙目運算符 |
11 |
&& |
邏輯與 |
表達式&&表達式 |
左到右 |
雙目運算符 |
12 |
|| |
邏輯或 |
表達式||表達式 |
左到右 |
雙目運算符 |
13 |
?: |
條件運算符 |
表達式1? 表達式2: 表達式3 |
右到左 |
三目運算符 |
14 |
= |
賦值運算符 |
變量=表達式 |
右到左 |
|
/= |
除後賦值 |
變量/=表達式 |
|||
*= |
乘後賦值 |
變量*=表達式 |
|||
%= |
取模後賦值 |
變量%=表達式 |
|||
+= |
加後賦值 |
變量+=表達式 |
|||
-= |
減後賦值 |
變量-=表達式 |
|||
<<= |
左移後賦值 |
變量<<=表達式 |
|||
>>= |
右移後賦值 |
變量>>=表達式 |
|||
&= |
按位與後賦值 |
變量&=表達式 |
|||
^= |
按位異或後賦值 |
變量^=表達式 |
|||
|= |
按位或後賦值 |
變量|=表達式 |
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15 |
, |
逗號運算符 |
表達式,表達式,… |
左到右 |
從左向右順序運算 |
Operator | Description | Example | Overloadable |
Group 1 (no associativity) | |||
:: | Scope resolution operator | Class::age = 2; | NO |
Group 2 | |||
() | Function call | isdigit('1') | YES |
() | Member initalization | c_tor(int x, int y) : _x(x), _y(y*10){}; | YES |
[] | Array access | array[4] = 2; | YES |
-> | Member access from a pointer | ptr->age = 34; | YES |
. | Member access from an object | obj.age = 34; | NO |
++ | Post-increment | for( int i = 0; i < 10; i++ ) cout << i; | YES |
-- | Post-decrement | for( int i = 10; i > 0; i-- ) cout << i; | YES |
const_cast | Special cast | const_cast<type_to>(type_from); | NO |
dynamic_cast | Special cast | dynamic_cast<type_to>(type_from); | NO |
static_cast | Special cast | static_cast<type_to>(type_from); | NO |
reinterpret_cast | Special cast | reinterpret_cast<type_to>(type_from); | NO |
typeid | Runtime type information |
cout « typeid(var).name(); cout « typeid(type).name(); |
NO |
Group 3 (right-to-left associativity) | |||
! | Logical negation | if( !done ) … | YES |
not | Alternate spelling for ! | ||
~ | Bitwise complement | flags = ~flags; | YES |
compl | Alternate spelling for ~ | ||
++ | Pre-increment | for( i = 0; i < 10; ++i ) cout << i; | YES |
-- | Pre-decrement | for( i = 10; i > 0; --i ) cout << i; | YES |
- | Unary minus | int i = -1; | YES |
+ | Unary plus | int i = +1; | YES |
* | Dereference | int data = *intPtr; | YES |
& | Address of | int *intPtr = &data; | YES |
new | Dynamic memory allocation |
long *pVar = new long; MyClass *ptr = new MyClass(args); |
YES |
new [] | Dynamic memory allocation of array | long *array = new long[n]; | YES |
delete | Deallocating the memory | delete pVar; | YES |
delete [] | Deallocating the memory of array | delete [] array; | YES |
(type) | Cast to a given type | int i = (int) floatNum; | YES |
sizeof | Return size of an object or type |
int size = sizeof floatNum; int size = sizeof(float); |
NO |
Group 4 | |||
->* | Member pointer selector | ptr->*var = 24; | YES |
.* | Member object selector | obj.*var = 24; | NO |
Group 5 | |||
* | Multiplication | int i = 2 * 4; | YES |
/ | Division | float f = 10.0 / 3.0; | YES |
% | Modulus | int rem = 4 % 3; | YES |
Group 6 | |||
+ | Addition | int i = 2 + 3; | YES |
- | Subtraction | int i = 5 - 1; | YES |
Group 7 | |||
<< | Bitwise shift left | int flags = 33 << 1; | YES |
>> | Bitwise shift right | int flags = 33 >> 1; | YES |
Group 8 | |||
< | Comparison less-than | if( i < 42 ) … | YES |
<= | Comparison less-than-or-equal-to | if( i <= 42 ) ... | YES |
> | Comparison greater-than | if( i > 42 ) … | YES |
>= | Comparison greater-than-or-equal-to | if( i >= 42 ) ... | YES |
Group 9 | |||
== | Comparison equal-to | if( i == 42 ) ... | YES |
eq | Alternate spelling for == | ||
!= | Comparison not-equal-to | if( i != 42 ) … | YES |
not_eq | Alternate spelling for != | ||
Group 10 | |||
& | Bitwise AND | flags = flags & 42; | YES |
bitand | Alternate spelling for & | ||
Group 11 | |||
^ | Bitwise exclusive OR (XOR) | flags = flags ^ 42; | YES |
xor | Alternate spelling for ^ | ||
Group 12 | |||
| | Bitwise inclusive (normal) OR | flags = flags | 42; | YES |
bitor | Alternate spelling for | | ||
Group 13 | |||
&& | Logical AND | if( conditionA && conditionB ) … | YES |
and | Alternate spelling for && | ||
Group 14 | |||
|| | Logical OR | if( conditionA || conditionB ) ... | YES |
or | Alternate spelling for || | ||
Group 15 (right-to-left associativity) | |||
? : | Ternary conditional (if-then-else) | int i = (a > b) ? a : b; | NO |
Group 16 (right-to-left associativity) | |||
= | Assignment operator | int a = b; | YES |
+= | Increment and assign | a += 3; | YES |
-= | Decrement and assign | b -= 4; | YES |
*= | Multiply and assign | a *= 5; | YES |
/= | Divide and assign | a /= 2; | YES |
%= | Modulo and assign | a %= 3; | YES |
&= | Bitwise AND and assign | flags &= new_flags; | YES |
and_eq | Alternate spelling for &= | ||
^= | Bitwise exclusive or (XOR) and assign | flags ^= new_flags; | YES |
xor_eq | Alternate spelling for ^= | ||
|= | Bitwise normal OR and assign | flags |= new_flags; | YES |
or_eq | Alternate spelling for |= | ||
<<= | Bitwise shift left and assign | flags <<= 2; | YES |
>>= | Bitwise shift right and assign | flags >>= 2; | YES |
Group 17 | |||
throw | throw exception | throw EClass(“Message”); | NO |
Group 18 | |||
, | Sequential evaluation operator | for( i = 0, j = 0; i < 10; i++, j++ ) … | YES |