javascript - Check if a textbox contains numbers only

Question

How to check if a textbox contains numbers only?

While googling I came across this. But I'm wondering if isNumeric can be used for this purpose or if there are more simpler ways of checking if a textbox has a numeric value.

var query = $('#myText').val();
if (parseFloat(query) == NaN) {
    alert("query is a string");
} else {
    alert("query is numeric");
}

Answer 1

You can check if the user has entered only numbers using change event on input and regex.

$(document).ready(function() {
    $('#myText').on('change', function() {
        if (/^d+$/.test($(this).val())) {
            // Contain numbers only
        } else {
            // Contain other characters also
        }
    })
});

REGEX:

1. /: Delimiters of regex
2. ^: Starts with
3. d: Any digit
4. +: One or more of the preceding characters
5. $: End

Regex Visualization:

Demo

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If you want to allow only numbers, you can use input-number and pattern

<input type="number" pattern="d+" />