Change input text value if it is NaN using jQuery

Question

I want to change value of textbox to -999, if it is having a value of NaN. I have written some code but it is not working, please suggest me what I need to change in this.

if($('input[name="tt10"]').val() === NaN) {
$('input[name="tt10"]').val('-999');
}

<input name='tt10' value='NaN'>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>

Your edit is still incomplete - ".val()" gives a string. – freedomn-m Jul 25 '21 at 11:57 — freedomn-m, Jul 25 '21 at 11:57

score 1 · Accepted Answer · answered Jul 25 '21 at 11:48

You need to call .val() to get the value of the input. And since the value is a string, you need to compare it with a string.

if($('input[name="tt10"]').val() === 'NaN') {
    $('input[name="tt10"]').val('-999');
};

<input name='tt10' value='NaN'>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>

score 1 · Answer 2 · answered Jul 25 '21 at 11:49

You have to use .val() to get value from input field.
Like this:

$('input[name="tt10"]').val()

And with that value now, you can check if value of input is NaN or not:

if($('input[name="tt10"]').val() === 'NaN') {
    $('input[name="tt10"]').val('-999');
};

For more information you can visit official documentation.

Change input text value if it is NaN using jQuery

2 Answers2