annamull654 annamull654 - 1 month ago 8x
Javascript Question

how to format input box text as I am typing it

How do I format the number as I type it in the html input box?

so for example, I want to type the number 2000, the moment I type the 4th digit, the text (that's currently displayed in the textbox) will be automatically formatted to 2,000 (with a comma).

//my modified code based on Moob answer below

<input type="text" class="formattedNumberField" onkeyup="myFunc()">

$(".formattedNumberField").on('keyup', function(){
var n = parseInt($(this).val().replace(/\D/g,''),10);

function myFunc(){
// doing something else

while this code works perfect as shown in Moob Fiddle, its not working on my end maybe because I have another onkeyup event inside the inputbox???


Pure JS (Sans jQuery):

var fnf = document.getElementById("formattedNumberField");
fnf.addEventListener('keyup', function(evt){
    var n = parseInt(this.value.replace(/\D/g,''),10);
    fnf.value = n.toLocaleString();
}, false);

Native JS Example Fiddle

With jQuery:

$("#formattedNumberField").on('keyup', function(){
    var n = parseInt($(this).val().replace(/\D/g,''),10);
    //do something else as per updated question
    myFunc(); //call another function too

With jQuery Example Fiddle

To allow decimals:

$("#formattedNumberField").on('keyup', function(evt){
    if (evt.which != 110 ){//not a fullstop
        var n = parseFloat($(this).val().replace(/\,/g,''),10);

Obligatory Example