Im new to JavaScript event handling, I would like to trigger an event upon mousemove and left-click on a div element. My current implementation is to check that e.which == 1 when I trigger the mousemove event function. However, I have read that the e.which property is now deprecated (). My code:

div.addEventListener("mousemove", myEventFunction)

function myEventFunction(e){
    if (e.which == 1){
       //do something
    }

}

Is there any alternative to perform this operation?

Im new to JavaScript event handling, I would like to trigger an event upon mousemove and left-click on a div element. My current implementation is to check that e.which == 1 when I trigger the mousemove event function. However, I have read that the e.which property is now deprecated (https://developer.mozilla/en-US/docs/Web/API/KeyboardEvent/which). My code:

div.addEventListener("mousemove", myEventFunction)

function myEventFunction(e){
    if (e.which == 1){
       //do something
    }

}

Is there any alternative to perform this operation?

• javascript
• dom-events

• 1 @KevinKloet Nopes. It's for keyboard events. For mouse, it's button. Also, keycode is deprecated. – Praveen Kumar Purushothaman Commented Dec 21, 2016 at 15:59
• 1 didn't see the mouse event, my bad – Kevin Kloet Commented Dec 21, 2016 at 16:00
• Sure.. No worries. @KevinKloet – Praveen Kumar Purushothaman Commented Dec 21, 2016 at 16:00
• use the e.key instead to check – Prashanth Benny Commented Dec 21, 2016 at 16:01
• @PrashanthBenny Are you sure? What does it give? Dude, this is a MouseEvent! What you are telling is a KeyboardEvent! – Praveen Kumar Purushothaman Commented Dec 21, 2016 at 16:02

2 Answers 2

You can use event.button if it is gonna be a mouse event.

The MouseEvent.button read-only property indicates which button was pressed on the mouse to trigger the event.

function myEventFunction(e) {
    e = e || window.event;
    if ("buttons" in e) {
        return button;
    }
    var button = e.which || e.button;
    return button;
}

The above function returns the button value.

event.which is deprecated and may disappear from future browsers.

event.button should be used in any new code. Note the mapping from https://developer.mozilla/en-US/docs/Web/API/MouseEvent/button:

• 0: Main button pressed, usually the left button or the un-initialized state
• 1: Auxiliary button pressed, usually the wheel button or the middle button (if present)
• 2: Secondary button pressed, usually the right button
• 3: Fourth button, typically the Browser Back button
• 4: Fifth button, typically the Browser Forward button