Detect backspace and special characters using javascript

Question

I want to detect these two behaviours on an input field:

1)Backspace key

2)"@" and "#" key

By using jQuery's keypress function, I am able to detect the special characters but not backspace. LINK -> How to know if .keyup() is a character key (jQuery)

By using jQuery's keyup/keydown, I am able to detect backspace, but not special characters. LINK -> jQuery: keyPress Backspace won't fire?

How can I detect both the behaviours ?

NOTE: Keypress can detect backspace in firefox only. Chrome doesn't detect this.

What's wrong with keyup event? Not sure to understand your issue. Could you provide a jsFiddle? — A. Wolff, May 02 '14 at 14:19
With that, I cannot detect backspace on chrome. (check the link provided) — Ateev Chopra, May 02 '14 at 14:22
`keypress` isn't fired for backspace, `keyup` is. My question was regarding `keyup`. So what's wrong with using `keyup`??? Test it yourself here: http://jsfiddle.net/8W7uV/ EDIT: ok, i see now what you mean by "special keys" — A. Wolff, May 02 '14 at 14:24

score 0 · Accepted Answer · edited May 23 '17 at 12:20

0

You can use following snippet:

var keys = {};

$('input').keydown(function (e) {
    keys[e.which] = true;
});

$('input').keyup(function (e) {        
    getKeys();
    delete keys[e.which];    
});

function getKeys() {    
   if(keys[8]) {
        alert('bakspace pressed');
    }else if(keys[17] && keys[18] && keys[48]) {
        alert('@ pressed');
    }else if(keys[17] && keys[18] && keys[51]) {
        alert('# pressed');
    }    
}

DEMO

original post: https://stackoverflow.com/a/4954480/1414562

edited May 23 '17 at 12:20

Community

1
1

answered May 02 '14 at 14:38

A. Wolff

74,033
9
94
155

This won't work if i want to write in between 2 words. For example: "hey there" is already there, but i try to enter @sam in between "hey" and "there". Any ideas ? – Ateev Chopra May 02 '14 at 20:38
@user2962766 Updated answer to handle this case – A. Wolff May 03 '14 at 08:48
Now @ key is not detected. – Ateev Chopra May 05 '14 at 06:12

Detect backspace and special characters using javascript

1 Answers1

DEMO