classes in java

1public class Lightsaber {
2  // properties
3  private boolean isOn;
4  private Color color;
5  
6  // constructor
7  public Lightsaber(Color color) {
8    this.isOn = false;
9    this.color = color;
10  }
11  
12  // getters
13  public Color getColor() {
14    return color;
15  }
16  public boolean getOnStatus() {
17    return isOn;
18  }
19  
20  // setters
21  public void turnOn() {
22    isOn = true;
23  }
24  public void turnOff() {
25    isOn = false;
26  }
27}
28
29
30
31// Implementation in main method:
32public class test {
33  public static void main(String[] args) {
34    Lightsaber yoda = new Lightsaber(green);
35    yoda.turnOn();
36  }
37}
38    

1public class Puppy {
2   public Puppy(String name) {
3      // This constructor has one parameter, name.
4      System.out.println("Passed Name is :" + name );
5   }
6
7   public static void main(String []args) {
8      // Following statement would create an object myPuppy
9      Puppy myPuppy = new Puppy( "tommy" );
10   }
11}

1// this might help you understand how classes work
2public class MathTest {
3
4    public static void main(String[] args) {
5
6        class MathAdd {
7
8            int num1;
9            int num2;
10
11            public int addNumbers() {
12
13                int addThemUp = num1 + num2;
14                return addThemUp;
15            }
16        }
17
18        MathAdd addition = new MathAdd(); // create a new instance of the class
19
20        // you can access variables from the class 
21        addition.num1 = 10; 
22        addition.num2 = 20;
23
24        // and use the method from the class to add them up
25        System.out.println(addition.addNumbers());
26
27    }
28}

1
2public class HelloWorld {
3  public static void main(String[] args) {
4    
5    // how to use class in java
6    class User{
7    	
8    	int score;
9    }
10    
11    User dave = new User();
12    
13    dave.score = 20;
14    
15    System.out.println(dave.score);
16    
17 
18  }
19}
20

1Class is a blueprint or template which
2you can create as many objects as you 
3like. Object is a member or instance
4of a class.
5Class is declared using class keyword,
6Object is created through
7new keyword mainly. A class is a template
8  for objects. A class defines 
9object properties including a valid range
10    of values, and a default value. 
11A class also describes object behavior.

1public class Main {
2  int x = 5;
3
4  public static void main(String[] args) {
5    Main myObj = new Main();
6    System.out.println(myObj.x);
7  }
8}
9 
10