how to use class in java code example

Example 1: java class

public class Lightsaber {
  // properties
  private boolean isOn;
  private Color color;
  
  // constructor
  public Lightsaber(Color color) {
    this.isOn = false;
    this.color = color;
  }
  
  // getters
  public Color getColor() {
    return color;
  }
  public boolean getOnStatus() {
    return isOn;
  }
  
  // setters
  public void turnOn() {
    isOn = true;
  }
  public void turnOff() {
    isOn = false;
  }
}



// Implementation in main method:
public class test {
  public static void main(String[] args) {
    Lightsaber yoda = new Lightsaber(green);
    yoda.turnOn();
  }
}

Example 2: java class

//	Example : TestClass (Can be predefined or user-defined)
public class TestClass {
  // properties
  private int id = 111;
  
  // constructor
  public TestClass(){
    super();
  }
  
  // method
  public void test(){
    // some code here
  }
}

Example 3: using class in java

public class HelloWorld {
  public static void main(String[] args) {
   
   
   class Number{
   
   	int number;
   
   	public boolean isPos(){
   		if(number > 0){
   			return true;
   		} else {
   			return false;
   		}
   		
   	}
   }
   
   Number myNumber = new Number();
   
   myNumber.number = 7;
   
   if(myNumber.isPos()){
   	System.out.println(myNumber.number + " is positive!!!");
   } else {
   	System.out.println(myNumber.number + " is not positive!!!");
   }
   
  }
}