Javascript NaN function not working

Question

I am trying to validate a text box to enter only numbers and not alphabets using javascript NaN function. But i am not getting the correct output

<html>
<body>


<input type="text" id="demo">

<button onclick="myFunction();">Try it</button>

<script>
function myFunction() 
{

var x =document.getElementById("demo");
   if (isNaN(x))
     {
      alert("hi");
     }
    else
    {
    alert("world");
    }
   }
</script>

</body>
</html>

`document.getElementById("demo").value` - you need to get the value from the input, not the input itself — StudioTime, Oct 06 '16 at 12:57
The output is correct. Your expectations apparently are not. — , Oct 06 '16 at 12:57
in your example x is holding the element not the element value, change it to document.getElementById("demo").value — Amr Elgarhy, Oct 06 '16 at 12:58

score 0 · Answer 1 · answered Oct 06 '16 at 12:57

0

x in your code will be an HTMLInput object. It will never be a number.

You want to test the value of parseInt(x.value).

answered Oct 06 '16 at 12:57

David Hedlund

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Javascript NaN function not working

1 Answers1