枚举类型}+变量名是什么意思呢
在enum{} 后加变量type什么意思呢?
以及在联合体最后}value什么意思呢?
0: #include <iostream> 1: using namespace std; 2: 3: union SimpleUnion 4: { 5: int num; 6: char alphabet; 7: }; 8: 9: struct ComplexType 10: { 11: enum DataType 12: { 13: Int, 14: Char 15: } Type; 16: 17: union Value 18: { 19: int num; 20: char alphabet; 21: 22: Value() {} 23: ~Value() {} 24: }value; 25: }; 26: 27: void DisplayComplexType(const ComplexType& obj) 28: { 29: switch (obj.Type) 30: { 31: case ComplexType::Int: 32: cout << "Union contains number: " << obj.value.num << endl; 33: break; 34: 35: case ComplexType::Char: 36: cout << "Union contains character: " << obj.value.alphabet << endl; 37: break; 38: } 39: } 40: 41: int main() 42: { 43: SimpleUnion u1, u2; 44: u1.num = 2100; 45: u2.alphabet = 'C'; 46: cout << "sizeof(u1) containing integer: " << sizeof(u1) << endl; 47: cout << "sizeof(u2) containing character: " << sizeof(u2) << endl; 48: 49: ComplexType myData1, myData2; 50: myData1.Type = ComplexType::Int; 51: myData1.value.num = 2017; 52: 53: myData2.Type = ComplexType::Char; 54: myData2.value.alphabet = 'X'; 55: 56: DisplayComplexType(myData1); 57: DisplayComplexType(myData2); 58: 59: return 0; 60: }
#笔试题目##C/C++#