C++ 运算符优先级列表

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Precedence Operator Description Example Overloadable Associativity 1 :: Scope resolution operator Class::age = 2; no left to right 2 () Function call printf(“Hello world/n”); yes left to right () 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 dynamic_cast Runtime-checked type conversion Y& y = dynamic_cast<Y&>(x); no static_cast Unchecked type conversion Y& y = static_cast<Y&>(x); no reinterpret_cast Reinterpreting type conversion int const* p = reinterpret_cast<int const*>(0x1234); no const_cast Cast away/Add constness int* q = const_cast<int*>(p); no typeid Get type information std::type_info const& t = typeid(x); no 3 ! Logical negation if (!done) ... yes right to left 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 sizeof Size (of the type) of the operand in bytes size_t s = sizeof(int); no new Dynamic memory allocation long* pVar = new long; yes new [] Dynamic memory allocation of array long* array = new long[20]; 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 4 ->* Member pointer selector ptr->*var = 24; yes left to right .* Member object selector obj.*var = 24; no 5 * Multiplication int i = 2 * 4; yes left to right / Division float f = 10.0 / 3.0; yes % Modulus int rem = 4 % 3; yes 6 + Addition int i = 2 + 3; yes left to right - Subtraction int i = 5 - 1; yes 7 << Bitwise shift left int flags = 33 << 1; yes left to right >> Bitwise shift right int flags = 33 >> 1; yes 8 < Comparison less-than if (i < 42) ... yes left to right <= 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 9 == Comparison equal-to if (i == 42) ... yes left to righteq Alternate spelling for == != Comparison not-equal-to if (i != 42) ... yes not_eq Alternate spelling for != 10 & Bitwise AND flags = flags & 42; yes left to rightbitand Alternate spelling for & 11 ^ Bitwise exclusive OR (XOR) flags = flags ^ 42; yes left to right xor Alternate spelling for ^ 12 | Bitwise inclusive (normal) OR flags = flags | 42; yes left to right bitor Alternate spelling for | 13 && Logical AND if (conditionA && conditionB) ... yes left to right and Alternate spelling for && 14 || Logical OR if (conditionA || conditionB) ... yes left to right or Alternate spelling for || 15 ? : Ternary conditional (if-then-else) int i = a > b ? a : b; no right to left 16 = Assignment operator int a = b; yes right to left+= 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 17 throw throw exception throw EClass(“Message”); no 18 , Sequential evaluation operator for (i = 0, j = 0; i < 10; i++, j++) ... yes left to right