Javascript event and css

Question

I have a input box and submit button as html, I would like to enter any number in the input box and then the alert message will display if it's even or odd. If it's even than one of the paragraph text color will change to red else blue. Here's my code:

    <!doctype html>
    <html lang="en">
    <head>
    <script src="jsfile.js"></script>
    </head>

    <body>
    <input type="text" id="inputBox"/>
    <button type="button" onclick="AlertBox()">Submit</button>

    <p id="p12">My first paragraph</p>
    </body>

    </html>

External js file:

    function AlertBox()
    {
        var number=document.getElementById("inputBox").value; 
        if (number / 2 == 0)
        {
            alert(number + " is even and ok to go."); 
            document.getElementById("p12").style.color = "red";

        } else
        {
            alert(number + " is not even and not ok to go."); 
            document.getElementById("p12").style.color = "blue"; 
        }
    }

Try var number=parseInt(document.getElementById("inputBox").value); Also, number / 2 == 0 won't get you what you want, try the modulus operator: if(number % 2 == 0){...} — neilsimp1
– neilsimp1, Commented Jun 26, 2015 at 18:31

connexo · Accepted Answer · 2015-06-26 18:36:10Z

2

function AlertBox() {
  var number = document.getElementById("inputBox").value;
  if (number % 2 == 0) {
    alert(number + " is even and ok to go.");
    document.getElementById("p12").style.color = "red";

  } else {
    alert(number + " is not even and not ok to go.");
    document.getElementById("p12").style.color = "blue";
  }
}

<!doctype html>
<html lang="en">

<head>
  <script src="jsfile.js"></script>
</head>

<body>
  <input type="text" id="inputBox" />
  <button type="button" onclick="AlertBox()">Submit</button>

  <p id="p12">My first paragraph</p>
</body>

</html>

answered Jun 26, 2015 at 18:36

connexo

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Comments

Josh Rutherford · Accepted Answer · 2015-06-26 18:33:00Z

2

You can't test for a number being even with number/2 == 0. You need to use the modulo operator: number % 2 == 0.

answered Jun 26, 2015 at 18:33

Josh Rutherford

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