CODEWITHSUNDEEP
javaif-statementcalculator
Derek
Derek

Reputation: 11

I am trying to build a basic calculator using if statements

I am trying to make a basic calculator for class.

I came up with the code below but all it does it addition.

Even if I use -, *, or /.

Any tips?

Scanner input = new Scanner(System.in);
    String num1, num2, operation, function;

    System.out.println("Enter a simple equation: ");
    function = input.nextLine();
    int firstspace = function.indexOf(" ");
    num1 = (function.substring(0,firstspace));
    int lastspace = function.lastIndexOf(" ");
    operation = (function.substring(firstspace,lastspace));
    num2= (function.substring(lastspace+1,function.length()));
    double n1 = Double.parseDouble(num1);
    double n2 = Double.parseDouble(num2);



    if (operation.equals(" + "));
    {
        System.out.println("your answer is " + (n1 + n2));
    }
    if  (operation.equals(" - "))
    {
        System.out.println("your answer is " + (n1 - n2));
    }

    if (operation.equals(" / "))
    {
        System.out.println("your answer is " + (n1 / n2));
    }
    if (operation.equals(" * "))
    {
        System.out.println("your answer is " + ( n1*n2));
    }

}

}

Upvotes: 0

Views: 60

Answers (1)

Ratnakar Sadasyula
Ratnakar Sadasyula

Reputation: 315

From what I see your code has this issue

if (operation.equals(" + "));
{
    System.out.println("your answer is " + (n1 + n2));
}

Here you are putting a semi colon, which means when you run the code,it will execute this condition by default, so that means addition will always execute whether you like it or not.

So basically your code should be like this

if (operation.equals("+" ))
            {
                System.out.println("your answer is " + (n1 + n2));
            }
            if  (operation.equals("-"))
            {
                System.out.println("your answer is " + (n1 - n2));
            }

            if (operation.equals("/"))
            {
                System.out.println("your answer is " + (n1 / n2));
            }
            if (operation.equals("*"))
            {
                System.out.println("your answer is " + ( n1*n2));
            }

Hope this helps

Upvotes: 1

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