Disable backspace and delete key with javascript in IE

Question

Anyone know how can I disable backspace and delete key with Javascript in IE? This is my code below, but seems it's not work for IE but fine for Mozilla.

onkeydown="return isNumberKey(event,this)"

function isNumberKey(evt, obj)
{

    var charCode = (evt.which) ? evt.which : evt.keyCode
    if (charCode == 8 || charCode == 46) return false;

    return true;
}

I would start by reading on the OnKeyUp/onKeyDown events and what the Event object members are. This should provide you all the data you need. — Itay Moav -Malimovka, Mar 20 '09 at 01:11

Joel · Accepted Answer · 2015-01-12T17:36:11.663

13

This event handler works in all the major browsers.

function onkeyup(e) {
    var code;
    if (!e) var e = window.event; // some browsers don't pass e, so get it from the window
    if (e.keyCode) code = e.keyCode; // some browsers use e.keyCode
    else if (e.which) code = e.which;  // others use e.which

    if (code == 8 || code == 46)
        return false;
}

You can attach the event to this function like:

<input onkeyup="return onkeyup()" />

edited Jan 12 '15 at 17:36

answered Mar 20 '09 at 01:12

Joel

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It should be in `onkeydown` not in `onkeyup` – Bipin Jul 10 '19 at 11:41

score 5 · Answer 2 · edited May 23 '17 at 12:30

5

update based on @JoeCoders comment and the 'outdatedness' of my answer, I revised it.

document.querySelector([text input element]).onkeydown = checkKey;
function checkKey(e) {
    e = e || event;
    return !([8, 46].indexOf(e.which || e.keyCode || e.charCode) > -1);
}

See also this jsFiddle

edited May 23 '17 at 12:30

Community

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answered Mar 20 '09 at 07:58

KooiInc

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hmm, I'm pretty sure I've used that event attachment in all the big browsers (ie, ff, safari, chrome, opera). – Joel Mar 23 '09 at 14:07
I tried this code in jsFiddle (http://jsfiddle.net/x9tnxqLt/2/) and I can't get it to work in IE11, Firefox 35, or Chrome 40. It intercepts the keyup event and gets the code, but even when false is returned the browser still deletes characters from the input when backspace or delete are pressed. Joel Potter's code doesn't work either. – EricP Feb 05 '15 at 22:03
Rather an old answer: the jsfiddle @ http://jsfiddle.net/KooiInc/9r6bvaLd/ may work better – KooiInc Feb 07 '15 at 08:27

score 3 · Answer 3 · answered Jun 01 '14 at 08:25

This code cancels backspace action.

window.onkeydown = function (event) {

    if (event.which == 8) { 

         event.preventDefault();   // turn off browser transition to the previous page 

                 // put here code you need 

        }; 

};

score 2 · Answer 4 · answered Nov 21 '11 at 11:26

$(document).keydown(function(e) {
    if (e.keyCode === 8) {
        var element = e.target.nodeName.toLowerCase();
        if ((element != 'input' && element != 'textarea') || $(e.target).attr("readonly")) {
            return false;
        }
    }
});

Disable backspace and delete key with javascript in IE

4 Answers4

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