C++中的delete与nullptr
1 #include <iostream> 2 #include <list> 3 #include <string> 4 5 using namespace std; 6 7 8 class Geometry { 9 public: 10 string getName1() 11 { 12 return "test"; 13 } 14 string getName2() 15 { 16 return name; 17 } 18 19 friend ostream& operator<<(ostream &out, const Geometry & geometry) { 20 return out << "Name: " << geometry.name; 21 } 22 private: 23 string name = "test"; 24 }; 25 26 27 int main(int argc, char** argv) 28 { 29 Geometry* g = new Geometry(); 30 cout << "== After new operator ==" << endl; 31 cout << "指针指向内存的值：" << * g << endl; 32 cout << "指针指向内存的地址：" << g << endl; 33 cout << "指针本身的地址：" << &g << endl; 34 delete g; 35 cout << endl << "== After delete operator ==" << endl; 36 // cout << "指针指向内存的值：" << * g << endl; // 程序崩溃 37 cout << "指针指向内存的地址：" << g << endl; 38 cout << "指针本身的地址：" << &g << endl; 39 g = nullptr; 40 cout << endl << "== After setNullptr operator ==" << endl; 41 // cout << "指针指向内存的值：" << * g << endl; // 程序崩溃 42 cout << "指针指向内存的地址：" << g << endl; 43 cout << "指针本身的地址：" << &g << endl; 44 45 cout << endl << g->getName1() << endl; 46 // cout << g->getName2() << endl; // 程序崩溃 47 return 0; 48 }
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