problem in understanding

I am facing problems in understanding how calling function works,how to call a function in another function and recurrsions can you please help me out

Answers

•   
  

  The best way to get is to do all the steps on a paper. For example, let’s take the factorial function:

  int factorial( int a ) /* function */
  {
      if( a == 0 || a == 1)
      {
          return 1;
      }
      else
      {
          return a*factorial(a-1);
      }
  }
  

  Let’s call factorial(2).

  On a paper, you can write all the steps i.e., firstly, a is not 0 or 1 so, 2*(factorial(1)) will be returned. Just hold up here and again do the same for factorial(1), this will return 1 and finally, you will replace 2*(factorial(1)) with 2*1.

  
  

---