56 lines
922 B
C++
56 lines
922 B
C++
// = 赋值重载
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// 注意 = 重载时，可能会调用类本身的拷贝构造函数。如果左值是没有创建的对象时，
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// 会调用类的拷贝构造函数
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#include <iostream>
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#include <cstring>
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#include <cstdlib>
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using namespace std;
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class A
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{
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private:
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int x;
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public:
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A(int x) : x(x)
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{
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cout << "A(int x)" << endl;
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}
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A(const A &obj)
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{
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cout << "A(A &obj)" << endl;
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this->x = obj.x;
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}
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A &operator=(const A &other)
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{
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cout << "A &operator=(A&other)" << endl;
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this->x = other.x;
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return *this;
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}
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public:
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void show()
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{
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cout << "x = " << x << endl;
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}
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};
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int main()
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{
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A a1(100), a2(200);
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A a4 = 300; // A(300)
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a4 = 400; // operator=()
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A a3 = a1; // A(a1)
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a3.show();
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a3 = a2; // operator=() 调用赋值重载函数
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a3.show();
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a3 = a4;
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a3.show();
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return 0;
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}
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