Is the shiftkey held down in JavaScript

Question

I have written a JS function that only allow numbers to be entered. A copy of that function is below:

function NumbersOnly(e) {
    var evt = e || window.event;
    if (evt) {
        var keyCode = evt.charCode || evt.keyCode;
        //Allow tab, backspace and numbers to be pressed, otherwise return false for everything.
        //(keyCode>=96 && keyCode<=105) are the numpad numbers        
        if ((keyCode >= 48 && keyCode <= 57) || (keyCode >= 96 && keyCode <= 105) || keyCode === 9 || keyCode === 8) {


        }
        else {

            evt.returnValue = false;
        }
    }
}

This function works fine with all the numbers but my problem happens when the shift key is held down and one of the number keys is pressed. The value returned is one of the characters above the numbers. So for example if I hold down shift and press 7, '&' is returned but the keyCode is still 55!! I would have expected that to be different.

So my question is how do I check if the shift key is being held down. I've tried the following check but this didn't work:

    if (keyCode === 16) {
        evt.returnValue = false;
    }
    else {

        if ((keyCode >= 48 && keyCode <= 57) || (keyCode >= 96 && keyCode <= 105) || keyCode === 9 || keyCode === 8) {


        }
        else {

            evt.returnValue = false;
        }
    }

I'm using ASP.NET 4.0.

Any help would be gratefully received.

Thanks in advance.

If you give the evt in console.log, you'll see shiftKey attribute, if shift key is pressed, it'll become true — Ranganadh Paramkusam, May 15 '12 at 10:55

score 16 · Accepted Answer · answered May 15 '12 at 11:02

16

You can check if shift key is pressed using :

if(evt.shiftKey) {
 ...  //returns true if shift key is pressed

answered May 15 '12 at 11:02

Sudhir Bastakoti

99,167
15
158
162

@Sajad, you're missing the point. 'evt' is just a variable, 'evt' is used in my answer in the context of the question posted above.. see the variable 'evt' in the question, line :: var evt = e || window.event; I hope you get it now. – Sudhir Bastakoti Aug 05 '15 at 07:15
aha, I got it, I did not read the question. sorry - Also that is *weird*, I used of `event`, and worked correctly. – Shafizadeh Aug 05 '15 at 07:58
Because `event` is a global variable corresponding to most recent event. – Alexander Tsepkov Jan 20 '17 at 04:30

score 0 · Answer 2 · answered Sep 05 '17 at 21:05

0

Use event.key instead of charCode. No more magic numbers!

function onEvent(event) {
    const key = event.key; // "a", "1", "Shift", etc.
    if (isFinite(key)) { // Is number
        // Do work
    }
};

Mozilla Docs

Supported Browsers

answered Sep 05 '17 at 21:05

Gibolt

42,564
15
187
127

score 0 · Answer 3 · answered Aug 23 '20 at 13:36

0

use keypress for holding any key isntead of keydown

answered Aug 23 '20 at 13:36

OneManFunction

31
2
5

keypress is deprecated. – Tal Kohavy Aug 07 '21 at 07:56

Is the shiftkey held down in JavaScript

3 Answers3

Linked