Checking isnan value by javascript is not working

Question

1.00/5 (1 vote)

See more:

I am trying to do login and logout task. If User login then alert login value else alert Empty but it is not properly set. it always return "Empty" Value even though "gg" has value.

<button id="btn" onclick="Test()" style="width:150px; height:40px;background-color:blue;color:white;">Pay Online</button>

function Test(){

            var re= parseInt(sessionStorage.getItem("myUser1"));
            document.getElementById('loveuser').value=re;
            var gg=document.getElementById('loveuser');

            if(!isNaN(gg)){
                alert(gg);
            }else{
                alert("Empty");
            }

        }

"gg" always retrun "Empty" Not "gg" value even though it has value. What's wrong?.

What I have tried:

trying from two days via online

Posted 28-Feb-23 18:38pm

MAHESH WAGHELA

Updated 28-Feb-23 22:14pm

Add a Solution

Comments

[no name] 1-Mar-23 1:31am

it seems "sessionStorage.getItem("myUser1")" is empty..
your isNaN works.

https://developer.mozilla.org/fr/docs/Web/JavaScript/Reference/Global_Objects/isNaN

MAHESH WAGHELA 1-Mar-23 2:46am

Thx Its Now Working

1 solution

Add a Solution

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Richard Deeming · Accepted Answer · 2023-02-28T22:14:00

Quote:

JavaScript

var gg=document.getElementById('loveuser');
if (!isNaN(gg)) {

Your gg variable contains the HTML element itself, not the value of that element.

An HTML element is not a number, so your code will always display "Empty".

Change your code to test the value of the element instead.

JavaScript

var gg = document.getElementById('loveuser').value;

Checking isnan value by javascript is not working

1 solution

Solution 1

Add your solution here

Preview 0

Checking isnan value by javascript is not working

1 solution

Solution 1

Add your solution here

Preview 0

Existing Members

...or Join us