How to remove alt activity?

Question

Google Chrome

Hello everyone
I ran into such a problem: when I enter some text in input or div[contenteditable] I want my function to be called when alt is pressed, the
problem is that in Chrome (possibly in other browsers, not tested) when I click on alt focus is lost from the field (when pressed again, it returns back). Peculiar toggleFocus (joke for 300) The
question is how to make it so that when I press alt, only my function fires and nothing else?

Answer 1

On Windows, any window interprets pressing the alt key as an action that initiates the opening of the current window's menu. And, as a result, the focus of your input is lost.
To prevent this situation use preventDefault

var element = document.querySelector("#InputID");
element.onkeyup = function(e){
   var key = e.keyCode || e.which;
   if(key===18) {
      e.preventDefault();
   }
};

Answer 2

jsfiddle.net/QW01_01/8fexst0h