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[转]C++操作符号的优先级


原文地址:http://www.cppreference.com/wiki/operator_precedence
哈哈。以后不用到处去看书啦。谢谢那个哥们。
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

哎,效果没有那里好。看来操作还需要练习。呵呵

posted on 2009-04-01 13:44 shongbee2 阅读(989) 评论(0)  编辑 收藏 引用 所属分类: c/c++


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