1. string str="data"; object h2=str; 2. List h1 = new List (); 3. IEnumerable h3 = new List (); First and third code working fine. But second code is blowing error. Please expain me.

List represents strongly typed list of objects. So, you've to have the same type when creating and when declaring. List h1 = new List (); //This is allowed as T here is object List h1 = new List (); The above line is not allowed as it cannot string to object

Jinish, if we can assign child in to parent. string str="data"; object h2=str; Why we can't assign list of them. 2. List h1 = new List ();

Jinish, List h1 = new List (); above code is also failed.

List h1 = new List (); h1.add(str); Syntax-> list h1=new list () Description-> "T" is parameter yo have to declare as data type like string or integer