C++ Destructor Explained: Usage and Syntax

The C++ destructor is a special member function used to clean up object resources. It is automatically called when an object is deleted, goes out of scope, or is destroyed.

The purpose of using a destructor is to release the memory occupied by an object, close files, release locks, and avoid issues such as memory leaks or resource leaks.

In C++, the naming convention for a destructor is to precede the class name with a tilde (~), for example: ~ClassName(). The destructor has no return type and does not accept any parameters.

The usage of destructor is as follows:

1. The destructor is automatically called when the object is destroyed, without the need for manual intervention.
2. You can define a destructor in a class, and if one is not defined, the compiler will generate a default destructor.
3. The destructor can be inherited, and the destructor of the derived class will automatically call the destructor of the base class.
4. Destructors are typically used to release memory occupied by objects, close files, release locks, and other resources.
5. You can use delete in the destructor to release memory allocated through new.
6. The order of calling the destructor is opposite to the order of calling the constructor, first the derived class object is destroyed, then the base class object is destroyed.

It is important to note that if a class has a destructor defined, the object should be created using the new operator instead of being allocated on the stack. For example:

ClassName* obj = new ClassName();
// 使用对象
delete obj; // 调用析构函数释放内存

In conclusion, the destructor is a special member function used to clean up object resources, automatically called when an object is destroyed, allowing for the release of memory, closing files, releasing locks, etc., to prevent memory leaks or resource leakage issues.