Thread: I cant figure out why this code isn't doing what i want.

So I am trying to make a simple calculator using java code. I want it to ask the user what he/she wants to do, then based on the answer, execute the code. For some reason it just closes after asking "Is there anything else you want to do". Can anyone help?

Here's the code:

import java.util.Scanner;
 
public class calculator
{
    public static void main(String[] args )
    {
        Scanner user_input = new Scanner(System.in);
        System.out.print("Is there anything you would you like to do?");        
        if(user_input.next() .equals("no"))
            {System.out.println("Ok thanks for trying this program");}
        if(user_input.next() .equals("yes"))
            {System.out.println("Ok what would you ike to do?");}
        if(user_input .equals("multiply"))      
        {
            double firstNo, secondNo;        
            System.out.println("Please input the first number ");
            firstNo = Double.parseDouble(user_input.next());
            System.out.println("Please input the second number ");
            secondNo = Double.parseDouble(user_input.next());
            double finalProduct= firstNo * secondNo;
            System.out.println("The final product is "+finalProduct );
            System.out.println("Is there anything else you want me to do?");
            if(user_input.next() .equals("no"))
            {System.out.println("Ok thanks for trying this program");}
        }  
        if(user_input.next() .equals("divide"))      
        {
            double firstNo, secondNo;        
            System.out.println("Please input the first number ");
            firstNo = Double.parseDouble(user_input.next());
            System.out.println("Please input the second number ");
            secondNo = Double.parseDouble(user_input.next());
            double finalProduct= firstNo / secondNo;
            System.out.println("The final product is "+finalProduct );
            System.out.println("Is there anything else you want me to do?");
            if(user_input.next() .equals("no"))
            {System.out.println("Ok thanks for trying this program");}
        }
        if(user_input.next() .equals("add"))      
        {
            double firstNo, secondNo;        
            System.out.println("Please input the first number ");
            firstNo = Double.parseDouble(user_input.next());
            System.out.println("Please input the second number ");
            secondNo = Double.parseDouble(user_input.next());
            double finalProduct= firstNo + secondNo;
            System.out.println("The final product is "+finalProduct );
            System.out.println("Is there anything else you want me to do?");
            if(user_input.next() .equals("no"))
            {System.out.println("Ok thanks for trying this program");}
        }
    }
}

Your code is difficult to read. Please ensure that the if/else clauses are indented properly and then place between code tags to preserver formatting. See BBCodes below to see how to use code tags.

Regards,
Jim

Please edit your post and wrap your code with code tags:

[code]
**YOUR CODE GOES HERE**
[/code]

to get highlighting and preserve formatting.

it just closes after asking

Please copy the full contents of the console window from when you execute the program and paste it here so we can see what you are talking about.

Please post items as text in the thread, not as images or attachments.

--- Update ---

Is it the case that in the list of if statements in the code, that only one of them is expected to be true?
Normally when that is the case, multiple, mutually exclusive if statements are coded as if/else if/else statements to show that only one is expected to be true and when that one is found, the remaining if statements are skipped.

oh. How would i do that. Is there an elseif statement?
Edit: Ok i found out there is , now the only problem is that the program terminates right after doing one instance of itself. How do i link the end back to the beginning again? do i use a while loop. If so, how? Untitled.jpg

You have one fundamental problem. You take input from the Scanner to see if the answer is "no." But then you take input from the Scanner to see if the answer is "yes." You needed to use the original input. Also here are some suggestions:

1. Why check for yes if no is not entered? Wouldn't that be the only other alternative? If you check for yes and no, what are you going to do if neither is entered?
2. What happens if someone enters mixed case? Check the String class for some possible ways to cater to this problem.
3. The scanner has a nextDouble() method. No need to read a string and convert.

Regards,
Jim

Excellent attitude! Someone will be here to help.

Regards,
Jim

There is some non-standard coding used:
There shouldn't be a statement on the same line following a {
The } should not be hidden at the end of a statement.

What is the required input to do the add operation? How many times do you have to enter "add"?
Most users would expect to have to enter an operation just one time.