What is constructor in C++?

 A constructor is a member function of a class which initializes objects of a class. In C++, Constructor is automatically called when object(instance of class) create. It is special member function of the class.

 

class StackNode {
public:
	int val;
	StackNode* top;	// pointer for top
	StackNode* prev; // pointer for previous node

	// constructor
	StackNode (int x) {

		this->val = x; // save data
		prev = NULL;
	}
}

 

As you can see that, 'StackNode' is memeber function of StackNode class as a constructor. And there are some general characteristics for constructor.

 

• Constructor has same name as the class itself
• Constructors don’t have return type
• A constructor is automatically called when an object is created.
• If we do not specify a constructor, C++ compiler generates a default constructor for us (expects no parameters and has an empty body).

 

It is simple summary of constructor in C++.

 

Reference

[1] https://www.geeksforgeeks.org/constructors-c/