java a simple user class code example

Example 1: 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 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

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 4: 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!!!");
   }
   
  }
}