What is the purpose of using super constructor with props argument?

A child class constructor cannot make use of this reference until super() method has been called. The same applies for ES6 sub-classes as well. The main reason of passing props parameter to super() call is to access this.props in your child constructors.

Passing props:

Not passing props:

The above code snippets reveals that this.props is different only within the constructor. It would be the same outside the constructor.