Nrthugu

I actually started learning java and my question is why do we use parameters and what are the uses of them? If we can initialize data members then what's the need of parameters? Also, what's the difference between parameters and arguments.
Thanks

Parameters are giving information to a method about what it needs to do its job. For an example, a function to find the max number would have an array of numbers as a parameter.

A parameter is a variable in a method definition. When a method is called somewhere, the arguments are the data you pass into the method's parameters.

class A {

    void theMethod(String theParameter) {

        System.out.println(theParameter);

    }



    public static void main(String args) {

        String argument = "the argument";

        new A().theMethod(argument);

    }

}

The parameters are used as both local and global variables (initialization purpose), local variables means inside a method or a function and global variables we use as an instance variables, ie. Class variables which are initialized by parameters or arguments.
Generally, in Java we use constructor to initialize the class variables.
For example:

   class Circle {

           float r ;    // instance variable or class variable which has to be used globally 



      public Circle( float r){

          this.r = r; 

      }



     public void area(){

        float pi = 3.14f;

        float area = pi * r * r;

        System.out.println("Area of a circle is "+area);

     }



     public static void main(String args){

          Circle c = new Circle(23.2f);

          c.area();

     }

  }