[javascript] How to detect escape key press with pure JS or jQuery?

Possible Duplicate:
Which keycode for escape key with jQuery

How to detect escape key press in IE, Firefox and Chrome? Below code works in IE and alerts 27, but in Firefox it alerts 0

$('body').keypress(function(e){
    alert(e.which);
    if(e.which == 27){
        // Close my modal window
    }
});

Below is the code that not only disables the ESC key but also checks the condition where it is pressed and depending on the situation, it will do the action or not.

In this example,

e.preventDefault();

will disable the ESC key-press action.

You may do anything like to hide a div with this:

document.getElementById('myDivId').style.display = 'none';

Where the ESC key pressed is also taken into consideration:

(e.target.nodeName=='BODY')

You may remove this if condition part if you like to apply to this to all. Or you may target INPUT here to only apply this action when the cursor is in input box.

window.addEventListener('keydown', function(e){
    if((e.key=='Escape'||e.key=='Esc'||e.keyCode==27) && (e.target.nodeName=='BODY')){
        e.preventDefault();
        return false;
    }
}, true);

Best way is to make function for this

FUNCTION:

$.fn.escape = function (callback) {
    return this.each(function () {
        $(document).on("keydown", this, function (e) {
            var keycode = ((typeof e.keyCode !='undefined' && e.keyCode) ? e.keyCode : e.which);
            if (keycode === 27) {
                callback.call(this, e);
            };
        });
    });
};

EXAMPLE:

$("#my-div").escape(function () {
    alert('Escape!');
})

i think the simplest way is vanilla javascript:

document.onkeyup = function(event) {
   if (event.keyCode === 27){
     //do something here
   }
}

Updated: Changed key => keyCode

Using JavaScript you can do check working jsfiddle

document.onkeydown = function(evt) {
    evt = evt || window.event;
    if (evt.keyCode == 27) {
        alert('Esc key pressed.');
    }
};

Using jQuery you can do check working jsfiddle

jQuery(document).on('keyup',function(evt) {
    if (evt.keyCode == 27) {
       alert('Esc key pressed.');
    }
});

check for keyCode && which & keyup || keydown

$(document).keydown(function(e){
   var code = e.keyCode || e.which;
   alert(code);
});

The keydown event will work fine for Escape and has the benefit of allowing you to use keyCode in all browsers. Also, you need to attach the listener to document rather than the body.

Update May 2016

keyCode is now in the process of being deprecated and most modern browsers offer the key property now, although you'll still need a fallback for decent browser support for now (at time of writing the current releases of Chrome and Safari don't support it).

Update September 2018 evt.key is now supported by all modern browsers.

document.onkeydown = function(evt) {_x000D_
    evt = evt || window.event;_x000D_
    var isEscape = false;_x000D_
    if ("key" in evt) {_x000D_
        isEscape = (evt.key === "Escape" || evt.key === "Esc");_x000D_
    } else {_x000D_
        isEscape = (evt.keyCode === 27);_x000D_
    }_x000D_
    if (isEscape) {_x000D_
        alert("Escape");_x000D_
    }_x000D_
};

Click me then press the Escape key

Pure JS

you can attach a listener to keyUp event for the document.

Also, if you want to make sure, any other key is not pressed along with Esc key, you can use values of ctrlKey, altKey, and shifkey.

 document.addEventListener('keydown', (event) => {
        
        if (event.key === 'Escape') {
         //if esc key was not pressed in combination with ctrl or alt or shift
            const isNotCombinedKey = !(event.ctrlKey || event.altKey || event.shiftKey);
            if (isNotCombinedKey) {
                console.log('Escape key was pressed with out any group keys')
              
            }
        }
    });

On Firefox 78 use this ("keypress" doesn't work for Escape key):

function keyPress (e)(){
  if (e.key == "Escape"){
     //do something here      
  }
document.addEventListener("keyup", keyPress);

pure JS (no JQuery)

document.addEventListener('keydown', function(e) {
    if(e.keyCode == 27){
      //add your code here
    }
});