Explain Adding methods in java

Question

Methods

Answer 1

JavaScript is not the same as Java.
Did you mean JavaScript?
If so see this.

Brief explanation
https://www.w3schools.com/js/js_object_methods.asp

Detailed explanation

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_Objects#defining_methods

Answer 2

class Car {}

class Car2 extends Car {
void newMethod() {}
}

Answer 3

Adding methods?