JavaScript Extremely weird behavior of the "keyup" event handler. I don't understand anything.

[Jaroslav Tavgen]

Guys, I just don't get it. I don't see ANY logics here. Could you help me?

function it_makes_no_sense_whatsoever(event){
  console.log(event.keyCode);
  console.log(event.keyСode==37);
  console.log(event.keyСode===37);
  console.log(parseInt(event.keyСode)==37);
  console.log(parseInt(event.keyСode)===37);
}
document.addEventListener(`keyup`, it_makes_no_sense_whatsoever);

If I apply this code and then press the Left Arrow, the console prints the following:

37
false
false
false
false

​

But WHY?​

 

[Jaroslav Tavgen]

Solved: the letter "C" in "event.keyCode" was cyrrllic.