Difference between initializer and default initializer list in c++ [duplicate]

Answer 1

The purpose of default initialization list is to initialize the constant variable with in the class. Because the constant variable is initialized before the object is initialized.

I provide one sample to explain the difference between these two initializations:

 class A
   {
       private:
          const int x;

  };

  A::A():x(5)        //this code works fine
  {

    }

    A::A()       //this code is wrong.const variable is not initialized once object         
   {
    x=5;
    }