jquery check if value is not null / empty or NaN

Question

sI'm currently checking if value is Nan using jQuery and would like to extend the check to not null or empty as well but not sure on how to do this, here's my code;

<script type="text/javascript"> // ensure quantity textbox is numeric
$(document).ready(function () {
    $('[id$=txtQuantity]').change(function () {
        if(isNaN(this.value)) {
            alert("Please ensure the quantity specified is numeric");
            $(this).val("1");
        }
        else{
            $(this).val(this.value);
        }
    });
});

Change if(isNaN(this.value)) { to if(!this.value || isNaN(this.value)) { — Royi Namir
– Royi Namir, Commented Sep 16, 2015 at 14:17
If think he probably wants if(!this.value || isNaN(this.value)) in other words if its null or a NAN — Coding Flow
– Coding Flow, Commented Sep 16, 2015 at 14:19

Royi Namir · Accepted Answer · 2015-09-16 14:31:42Z

6

You can change :

if(isNaN(this.value))

To

if(!this.value || isNaN(this.value)) ...

But why don't you use :

jQuery.isNumeric ?

So :

if(!jQuery.isNumeric(this.value)) {
            alert("Please ensure the quantity specified is numeric");
            $(this).val("1");
        }
        else{
            $(this).val(this.value);
        }

edited Sep 16, 2015 at 14:31

answered Sep 16, 2015 at 14:21

Royi Namir

149k145 gold badges502 silver badges833 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Community · Accepted Answer · 2017-05-23 10:27:03Z

4

you can check for null directly like

(myVar !== null)

to check if the variable is empty you can do

(myVar !== '')

and for the numeric check either using isNaN() or $.isNumeric() may work but $.isNumeric() return more accurate boolean read more here

(isNaN(myVar)) or (!$.isNumeric(myVar))

all together

if ( (myVar !== null) || (myVar !== '') || (!$.isNumeric(myVar)) ){ ... }

edited May 23, 2017 at 10:27

CommunityBot

11 silver badge

answered Sep 16, 2015 at 14:45

santi6291

1642 silver badges9 bronze badges

Collectives™ on Stack Overflow

jquery check if value is not null / empty or NaN

2 Answers 2

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related