Gettin NaN value instead of integer

Question

I have a dropdown list and I'm passing the value to a function which performs a task when the value changes.

<li style="background-color:white; float:right">
  <select id="dpItems" onchange='loadScript();'>
    <option value="">Select</option>
    <option value="5">5</option>
    <option value="10">10</option>
    <option value="20">20</option>
    <option value="50">50</option> 
  </select> items per page
</li>

And the javascript that is getting the value as follows:

function loadScript() {
  var newItems = parseInt($("#dpItems").val());
  alert('New value: ' + newItems);
  console.log('New value: ' + newItems);
}

But I'm always getting NaN value instead of the correct value on the option within the select. I tried changing the value on the option to 5 (without quotes) but same result.

Any ideas? Thanks in advance for any help.

The HTML calls "loadScript" but the function you posted is "updateItems()". How are they related? — Pointy, Jun 19 '18 at 23:51
My bad, the function is calling loadScript but when pasting I changed, sorry. — Carlos M, Jun 19 '18 at 23:58

score 2 · Answer 1 · answered Jun 20 '18 at 00:12

2

You can pass its value to the onchange function and it will not be undefined:

<select id="dpItems" onchange='loadScript(this.value);'>

answered Jun 20 '18 at 00:12

Ramenous

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1
8

score 0 · Answer 2 · answered Jun 19 '18 at 23:55

0

You're trying to convert undefined into an integer.

Number.isNaN(parseInt(undefined)) === true;

answered Jun 19 '18 at 23:55

Reactgular

52,335
19
158
208

Why it is undefined, I'm checking for the val, is not correct? – Carlos M Jun 19 '18 at 23:59
@CarlosM `$("#dpItems").val()` is yielding `undefined`. You might have more than one select with id `dpItems`. – Reactgular Jun 20 '18 at 00:00

Gettin NaN value instead of integer

2 Answers2