Why default argument constructor is called as default constructor

Question

Class A {
public:
       A(int i = 0, int k = 0) {} // default constructor WHY ??
       ~A() {}
};
int main()
{
  A a; // This creates object using defined default          


        

Answer 1

C++11 §12.1 Constructors

A default constructor for a class X is a constructor of class X that can be called without an argument.

This is the definition of default constructor. A constructor that supplies default arguments for all its parameters can be called without argument, thus fits the definition.