Which function is used to perform some action when the object is to be destroyed?

The function used to perform some action when the object is to be destroyed is called a destructor.

Here are the steps to use a destructor:

1. Define the destructor within the class. The destructor has the same name as the class but is preceded by a tilde (~). For example, if your class name is MyClass, your destructor will be ~MyClass().

2. Inside the destructor, write the code for the actions you want to perform when the object is destroyed. This could be releasing memory, closing files, or any other cleanup tasks.

3. The destructor is automatically called when the object goes out of scope or is explicitly deleted.

Note: A class can only have one destructor, and it cannot take arguments nor can it return a value.