Class Definition » Defining Method

Methods

Methods define actions that a class's objects (or instances) can do. A method has a declaration part and a body. The declaration part consists of a return value, the method name, and a list of arguments. The body contains code that perform the action. The return type of a method can be a primitive, an object, or void. The return type void means that the method returns nothing. The declaration part of a method is also called the signature of the method.

For example, here is the getSalary method that returns a double.

public class MainClass {   double getSalary() {     return 0.0;   } }

 Passing Objects to a Method

class Sphere {
  double radius; // Radius of a sphere

  Sphere() {

  }

  // Class constructor
  Sphere(double theRadius) {
    radius = theRadius; // Set the radius

  }

}

public class MainClass {
  public static void main(String[] arg){
    Sphere sp = new Sphere();
    
    aMethod(sp);
  }

  
  private static void aMethod(Sphere sp){
    System.out.println(sp);
  } 

 Returning From a Method 

public class MainClass {
  private int aField;

  public void aMethod() {

  }
  public double volume() {
    return 50;
  }
  
}

 

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