Calculator doesn't add two numbers it just writes them together like"2+2=22"

Question

<title>Calculator</title>

<script type="text/javascript">

    function Calculate(){

        var myWorker = document.getElementById('myOperation');
        var numberOne= document.getElementById('firstNumber').value;
        var numberTwo= document.getElementById('secondNumber').value;
        if (myWorker = "+") {
            var provideAnswer = (numberOne + numberTwo);
            var finalAnswer= document.getElementById('myAnswer');
            finalAnswer.innerHTML = provideAnswer;
        }

        else {

            alert('Please use Addition Symbol Only')

        }
    }
</script>

<h1>CALCULATOR</h1>

<br/>

<h2>Enter the first number</h2>
    <input type="number" id="firstNumber" />

<br/>
<br/>

<h2>Enter the Operation</h2>

    <input type="text" id="myOperation" />

<br/>
<br/>

<h2>Enter the second number</h2>
    <input type="number" id="secondNumber" />
    <input type="submit" value="Answer Is" onclick="Calculate()"/>
<br/>
<br/>

<h1 id="myAnswer">Your ANSWER Will be REPLACED by THIS TEXT</h1>

Look at the duplicate. It has the answer. See https://stackoverflow.com/a/4841405/989920 — evolutionxbox, Jun 24 '19 at 09:16
Are you sure? The answer I linked asks you to parse your value. You’re not doing that. — evolutionxbox, Jun 24 '19 at 09:21
I’m glad it’s solved, but make you understand _why_ you need to do this. — evolutionxbox, Jun 24 '19 at 09:26
You’ve got a single equals which means “assignment”. Use a triple equals `===` which means “compare value” (without type coercion). — evolutionxbox, Jun 24 '19 at 09:32
Because they both compare. Double equals just isn’t as strict. Take a look here: https://stackoverflow.com/questions/359494/which-equals-operator-vs-should-be-used-in-javascript-comparisons — evolutionxbox, Jun 24 '19 at 09:37
Can you make a separate question for this? I think that'd be a good idea. (Please remember to include a [mcve]). — evolutionxbox, Jun 24 '19 at 09:43
I see. Consider creating your own so his rep isn’t changed without his input. ;) — evolutionxbox, Jun 24 '19 at 10:41
Ha. It’s ok. You’re new to this. Next question you make, try to show as much effort as you can, add a [mcve], and remember to research before asking. — evolutionxbox, Jun 24 '19 at 10:44

score 0 · Answer 1 · edited Jun 24 '19 at 11:12

You need to parse the values to numbers first - quickest and simplest way is to use the unary + operator:

function Calculate() {

        
  var myWorker = document.getElementById('myOperation');      
  var numberOne = +document.getElementById('firstNumber').value;      
  var numberTwo = +document.getElementById('secondNumber').value;      
  if (myWorker == "+") {        
    var provideAnswer = (numberOne + numberTwo);        
    var finalAnswer = document.getElementById('myAnswer');        
    finalAnswer.innerHTML = provideAnswer;      
  } else {

            
    alert('Please use Addition Symbol Only')

          
  }    
}

<h1>CALCULATOR</h1>
<h2>Enter the first number</h2>
<input type="number" id="firstNumber" />
<h2>Enter the Operation</h2>
<input type="text" id="myOperation" />
<h2>Enter the second number</h2>
<input type="number" id="secondNumber" />
<input type="submit" value="Answer Is" onclick="Calculate()" />
<h1 id="myAnswer">Your ANSWER Will be REPLACED by THIS TEXT</h1>

_{(I modified your HTML markup slightly to remove newlines)}

What do you mean @IrshadAhmed? They're being used to add successfully above (see the `+` right after `var numberOne = `?) — Jack Bashford, Jun 24 '19 at 09:18
That's because you're using `=`. Change to `==` and it'll work. — Jack Bashford, Jun 24 '19 at 09:32

Calculator doesn't add two numbers it just writes them together like"2+2=22"

1 Answers1