creating class in java code example

Example 1: how to make a class in java

public class Main {
 public static void main (String[] args) {
	System.out.println("Hello World");
 } 
}

Example 2: classes in java

// this might help you understand how classes work
public class MathTest {

    public static void main(String[] args) {

        class MathAdd {

            int num1;
            int num2;

            public int addNumbers() {

                int addThemUp = num1 + num2;
                return addThemUp;
            }
        }

        MathAdd addition = new MathAdd(); // create a new instance of the class

        // you can access variables from the class 
        addition.num1 = 10; 
        addition.num2 = 20;

        // and use the method from the class to add them up
        System.out.println(addition.addNumbers());

    }
}

Example 3: using class in java

public class HelloWorld {
  public static void main(String[] args) {
    
    // how to use class in java
    class User{
    	
    	int score;
    }
    
    User dave = new User();
    
    dave.score = 20;
    
    System.out.println(dave.score);
    
 
  }
}

Example 4: using class in java

class Number {
    	
    	int number;
    	
    	// square numbers
    	public boolean isSquare(){
    		
    		double squareRoot = Math.sqrt(number);
    		
    		
    		if(squareRoot == Math.floor(squareRoot))
    		{
    			return true;
    		} else {
    			return false;
    		}
    		
    	}
    	
    	// triangular numbers
    	public boolean isTriangular(){
    		
    		int x = 1;
    		
    		int triangularNumber = 1;
    		
    		while(triangularNumber < number){
    			
    			x++;
    			triangularNumber = triangularNumber + x;
    			
    		}
    		
    		if(triangularNumber == number){
    			return true;
    		} else {
    			return false;
    		}
    	}
    }
    
    // testing 
    Number myNumber = new Number();
    myNumber.number = 16;
    
    System.out.println(myNumber.isSquare());

Example 5: class in java

Class is a blueprint or template which
you can create as many objects as you 
like. Object is a member or instance
of a class.
Class is declared using class keyword,
Object is created through
new keyword mainly. A class is a template
  for objects. A class defines 
object properties including a valid range
    of values, and a default value. 
A class also describes object behavior.

Example 6: using class in java

public class HelloWorld {
  public static void main(String[] args) {
    
    // how to use class in java
    class User{
    	
    	int score;
    	
    	// method that can be used outside the class
    	public boolean hasWon(){
    		if(score >= 100){
    			return true;
    		} else {
    			return false;
    		}
    	}
    }
    
    User dave = new User();
    
    dave.score = 20;
    
    System.out.println(dave.hasWon());
    
 
  }
}