52 lines
982 B
C++
52 lines
982 B
C++
// 动态创建对象(malloc / realloc / calloc 在堆中创建空间, new 关键字)
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#include <iostream>
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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)
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{
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this->x = x;
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cout << "A(int)" << endl;
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}
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~A()
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{
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cout << "~A()" << endl;
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}
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public:
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void init(int x)
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{
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this->x = x;
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cout << "init(int)" << endl;
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}
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void clean()
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{
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cout << "clean()" << endl;
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}
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};
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int main()
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{
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// 1) 使用 malloc 方式创建
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// cout << "A size is " << sizeof(A) << endl;
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// A *a1 = (A *)malloc(sizeof(A));
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// // a1->A(20); // 不允许显式调用构造函数
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// a1->init(20); // 初始化数据
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// a1->clean(); // 释放数据的空间
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// a1->~A(); // 析构函数可以显式调用
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// free(a1);
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// 2) new 方式创建，delete释放
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A *a1 = new A(1);
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delete a1; // 用完之后直接 delete 释放空间
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return 0;
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}
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