How to check SELECTED option is UNDEFINED or NOT in JQuery?

Asked Jan 10 '19 at 09:44

Active Jan 10 '19 at 10:12

Viewed 281 times

I want to check in if statement whether the select option value is undefined or not.

I tried like below. But it doesn't take effect

if ($('#Combo_DocType').find(':selected').val() === "undefined") {
        $('#failspan').text('undefined');
    }

For example:

if the user doesn't select any one of the options from ComboBox, it will be remain undefined, So I want to alert them,

edited Jan 10 '19 at 10:12

asked Jan 10 '19 at 09:44

Liam neesan

1

use `typeof` instead – treyBake Jan 10 '19 at 09:46
Please add some code, the question itself is not self explanatory – Gaurav joshi Jan 10 '19 at 09:46
try to use `undefined` not `"undefined"` coz the latter is a String and what you want to compare is the `undefined` value – j.ian.le Jan 10 '19 at 09:48
You're currently checking whether it's equal to the string "undefined", if you're checking against the `undefined` state, use `typeof` as treyBake says. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/typeof – DBS Jan 10 '19 at 09:48
@DBS I never tried with `typeof`, Could you please tell me how? – Liam neesan Jan 10 '19 at 09:50
2

https://stackoverflow.com/a/519157/1650337 – DBS Jan 10 '19 at 09:51
1

Are you trying to find a value explicitly set to the string `undefined`, or are you trying to check if anything has actually been selected? There's a better approach if you're trying the latter. – Rory McCrossan Jan 10 '19 at 09:52
@DBS ah, I shoulda tried actually looking instead of being lazy xD will rm my answer – treyBake Jan 10 '19 at 09:52
though here's the fiddle https://jsfiddle.net/dhsfxy7o/ – treyBake Jan 10 '19 at 09:53
@DBS `typeof` is working – Liam neesan Jan 10 '19 at 10:14
Possible duplicate of [JavaScript check if variable exists (is defined/initialized)](https://stackoverflow.com/questions/5113374/javascript-check-if-variable-exists-is-defined-initialized) – Calvin Nunes Jan 10 '19 at 10:46

0 Answers0