Simple Cal Using Java(Object Oriented Way)

Save each class in a separate .java file and compile the main class

Main Class

  
import java.util.Scanner;

public class SimpleCal {

    public static void main(final String args[]) {

    Scanner sc=new Scanner(System.in);

    System.out.println("\bWelcome to Simple Cal 2.0");
    System.out.println("\nEnter 1 to add two numbers");
    System.out.println("Enter 2 to substract second number from first number");
    System.out.println("Enter 3 to multiply two numbers");
    System.out.println("Enter 4 to divide first number from second number");
    System.out.println("\nEnter operation you want to perform");
    
    int opt=sc.nextInt();

    if(opt==1){

        Add ad = new Add();
        ad.add() ;

    }else if(opt==2){

        Sub sb= new Sub();
        sb.sub() ;

    }else if(opt==3){

        Multi mt= new Multi();
        mt.multi() ;

    }else if(opt==4){

        Div dv= new Div();
        dv.div() ;

    }else{

        System.out.println("Invalid operation");

    }

    }
    
}

Addition Class

 
import java.util.Scanner;

public class Add {

    Scanner sc=new Scanner(System.in);

    public void add(){

        System.out.print("Enter your first number: ");
        double num1=sc.nextDouble();
        System.out.print("Entre your second number: ");
        double num2=sc.nextDouble();
        double tot=num1+num2;

        System.out.println("Sum of two numbers is: "+tot);
    }
    
}

Subtract Class

import java.util.Scanner;

public class Sub {

    Scanner sc=new Scanner(System.in);

    public void sub(){
    
        System.out.print("Enter your firts number: ");
        double num1=sc.nextDouble();
        System.out.print("Enter youe second number: ");
        double num2=sc.nextDouble();

        double dif=num1-num2;

        System.out.println("Difference of two numbers is "+dif);
        
    }
    
}

Multiplication Class

  
import java.util.Scanner;

public class Multi {

    Scanner sc=new Scanner(System.in);

    public  void multi(){

    System.out.print("Enter your first number: ");
    double num1=sc.nextDouble();
    System.out.print("Enter your second number: ");
    double num2=sc.nextDouble();

    double product=num1*num2;

    System.out.println("Product of two numbers is "+product);

    }
    
}

Division Class

import java.util.Scanner;

public class Div {
    Scanner sc=new Scanner(System.in);

    public  void div(){

    System.out.print("Enter your first number: ");
    double num1=sc.nextDouble();
    System.out.print("Enter your second number: ");
    double num2=sc.nextDouble();
    
    double division=num1/num2;

    System.out.println("Division  of first number from second numbers is "+division);
    
    }
}