[Solved] IndexOf not working on childList [closed]

by 


public int indexOf(Object o) {
  if (o == null) {
  for (int i = 0; i < size; i++)
  if (elementData[i]==null)
  return i;
  } else {
  for (int i = 0; i < size; i++)
  if (o.equals(elementData[i]))
  return i;
  }
  return -1;
  }

This is actual method in Arraylist ,after reading i came to know that i must override the equal method in the class A since i am passing instance of A as a parameter .
finally it worked for me.

If yoy see above code

 if (o.equals(elementData[i]))

they are checking parameter class’s equal method.

solved IndexOf not working on childList [closed]