JQuery or JavaScript: How determine if shift key being pressed while clicking anchor tag hyperlink?

Question

I have an anchor tag that calls a JavaScript function.

With or without JQuery how do I determine if the shift key is down while the link is clicked?

The following code does NOT work because keypress is only fired if a "real key" (not the shift key) is pressed. (I was hoping it would fire if just the shift key alone was pressed.)

var shifted = false;

$(function() {                           
    $(document).keypress(function(e) {
        shifted = e.shiftKey;
        alert('shiftkey='+e.shiftkey);
    });

    $(document).keyup(function(e) {
        shifted = false;
    });
}

...

function myfunction() {
  //shift is always false b/c keypress not fired above
}

Answer 1

    $(document).on('keyup keydown', function(e){shifted = e.shiftKey} );

Answer 2

Here is the key code for each key stroke in JavaScript. You can use that and detect if the user has pressed the Shift key.

backspace           8
tab                 9
enter               13
shift               16
ctrl                17
alt                 18
pause/break         19
caps lock           20
escape              27
page up             33
page down           34
end                 35
home                36
left arrow          37
up arrow            38
right arrow         39
down arrow          40
insert              45
delete              46
0                   48
1                   49
2                   50
3                   51
4                   52
5                   53
6                   54
7                   55
8                   56
9                   57
a                   65
b                   66
c                   67
d                   68
e                   69
f                   70
g                   71
h                   72
i                   73
j                   74
k                   75
l                   76
m                   77
n                   78
o                   79
p                   80
q                   81
r                   82
s                   83
t                   84
u                   85
v                   86
w                   87
x                   88
y                   89
z                   90
left window key     91
right window key    92
select key          93
numpad 0            96
numpad 1            97
numpad 2            98
numpad 3            99
numpad 4            100
numpad 5            101
numpad 6            102
numpad 7            103
numpad 8            104
numpad 9            105
multiply            106
add                 107
subtract            109
decimal point       110
divide              111
f1                  112
f2                  113
f3                  114
f4                  115
f5                  116
f6                  117
f7                  118
f8                  119
f9                  120
f10                 121
f11                 122
f12                 123
num lock            144
scroll lock         145
semi-colon          186
equal sign          187
comma               188
dash                189
period              190
forward slash       191
grave accent        192
open bracket        219
back slash          220
close braket        221
single quote        222

Not all browsers handle the keypress event well, so use either the key up or the key down event, like this:

$(document).keydown(function (e) {
    if (e.keyCode == 16) {
        alert(e.which + " or Shift was pressed");
    }
});

Answer 3

For mouse events, I know that in Firefox at least the "shiftKey" property on the event object will tell you if the shift key is down. It's documented at MSDN but I haven't tried it in forever so I don't recall if IE does this right.

Thus you should be able to check for "shiftKey" on the event object in your "click" handler.

Answer 4

I had a similar problem, trying to capture a 'shift+click' but since I was using a third party control with a callback rather than the standard click handler, I didn't have access to the event object and its associated e.shiftKey.

I ended up handling the mouse down event to record the shift-ness and then using it later in my callback.

    var shiftHeld = false;
    $('#control').on('mousedown', function (e) { shiftHeld = e.shiftKey });

Posted just in case someone else ends up here searching for a solution to this problem.

Answer 5

For checking if the shiftkey is pressed while clicking with the mouse, there is an exact property in the click event object: shiftKey (and also for ctrl and alt and meta key): https://www.w3schools.com/jsref/event_shiftkey.asp

So using jQuery:

$('#anchor').on('click', function (e) {
    if (e.shiftKey) {
        // your code
    }
});

Answer 6

I have used a method to test if any specific key is pressed by storing the currently pressed key codes in an array:

var keysPressed = [],
    shiftCode = 16;

$(document).on("keyup keydown", function(e) {
    switch(e.type) {
        case "keydown" :
            keysPressed.push(e.keyCode);
            break;
        case "keyup" :
            var idx = keysPressed.indexOf(e.keyCode);
            if (idx >= 0)
                keysPressed.splice(idx, 1);
            break;
    }
});

$("a.shifty").on("click", function(e) {
    e.preventDefault();
    console.log("Shift Pressed: " + (isKeyPressed(shiftCode) ? "true" : "false"));
});

function isKeyPressed(code) {
    return keysPressed.indexOf(code) >= 0;
}

Here is the jsfiddle

Answer 7

The keypress event isn't triggered by all browsers when you click shift or ctrl, but fortunately the keydown event is.

If you switch out the keypress with keydown you might have better luck.

Answer 8

The excellent JavaScript library KeyboardJS handles all types of key presses including the SHIFT key. It even allows specifying key combinations such as first pressing CTRL+x and then a.

KeyboardJS.on('shift', function() { ...handleDown... }, function() { ...handleUp... });

If you want a simple version, head to the answer by @tonycoupland):

var shiftHeld = false;
$('#control').on('mousedown', function (e) { shiftHeld = e.shiftKey });

Answer 9

This works great for me:

function listenForShiftKey(e){
    var evt = e || window.event;
    if (evt.shiftKey) {
      shiftKeyDown = true;
    } else {
      shiftKeyDown = false;
    }
}

Answer 10

A more modular approach plus the ability to keep your this scope in the listeners:

var checkShift = function(fn, self) {
  return function(event) {
    if (event.shiftKey) {
      fn.call(self, event);
    }
    return true;
  };
};

$(document).on('keydown', checkShift(this.enterMode, this));

Answer 11

If anyone's looking to detect a given key and needs to know the status of the "modifiers" (as they are called in Java), i.e. Shift, Alt and Control keys, you can do something like this, which responds to keydown on key F9, but only if none of the Shift, Alt or Control keys is currently pressed.

jqMyDiv.on( 'keydown', function( e ){
    if( ! e.shiftKey && ! e.altKey && ! e.ctrlKey ){
        console.log( e );
        if( e.originalEvent.code === 'F9' ){
          // do something 
        }
    }
});

Answer 12

var shiftDown = false;
this.onkeydown = function(evt){
    var evt2 = evt || window.event;
    var keyCode = evt2.keyCode || evt2.which;       
    if(keyCode==16)shiftDown = true;
}
this.onkeyup = function(){
    shiftDown = false;
}

demo