Question

I am having trouble getting this program to work properly, it takes 2 numbers then does the type of math you tell it to do. I wrote this just to refresh my memory having not worked with java for a few months. Here is the code:

import java.util.Scanner;
public class math {
    public static void main(String[] args){
        Scanner one = new Scanner(System.in);
        Scanner two = new Scanner(System.in);
        System.out.print("Enter a number: ");
        int n1 = one.nextInt();
        System.out.print("Enter a second number: ");
        int n2 = one.nextInt();
        System.out.print("Add, subtract, multiply, or divide? ");
        String f = two.nextLine();
        System.out.println(f);
        if (f=="add"){
            System.out.println(n1 + n2);
        }else if (f=="subtract") {
            if (n1>n2){
                System.out.println(n1 - n2);
            }else{
                System.out.println(n2 - n1);
            }
        }else if (f=="multiply"){
            System.out.println(n1 * n2);
        }else if (f=="divide"){
            if (n1>n2){
                System.out.println(n1 / n2);
            }else{
                System.out.println(n2 / n1);
            }
        }
    }
}

Edit: Thank you all, it works with f.equals()

Answer 1

Your String comparisons need to be changed to use String.equals() instead of ==:

if (f=="add"){

To

if ("add".equals(f)){

and

    }else if (f=="subtract") {

to

    }else if ("subtract".equals(f)) {

etc.