super keyword without extends to the super class

Question

There is a code of simple program. In constructor, super() is called without extends to the super class, I can not understand what will does this in this situat

Answer 1

Constructor from your code works the same as:

Student(String name, int rollNum){
    this.name = name;
    this.rollNum = rollNum;
}

In your question super() is just calling constructor of Object class.