JavaScript key holding down and release

Question

I can control my bot through web. These are its url-

• forward- https://172.0.0.1/forward
• backward- https://172.0.0.1/backward
• left- https://172.0.0.1/left
• right- https://172.0.0.1/right
• stop- https://172.0.0.1/stop
  

I am using html button to do this. But I want to control it with "arrow" key of keyboard. My idea is if I press and hold up arrow key then the bot will go forward(https://172.0.0.1/forward) and if I release the up arrow key then the bot will Stop(https://172.0.0.1/stop) going. and the same thing to

• backward - "down arrow"
• left- "left arrow"
• right-"right arrow"

I'm not familiar with JavaScript Can you please help me...

Answer 1

try like this.

window.addEventListener('keydown',function(event){
if(event.keyCode===37) { //left
}
if(event.keyCode===38) { //up
}

if(event.keyCode===39) { //right
}
if(event.keyCode===40) { //down
}

});

UPDATE

window.addEventListener('keyup',function(event){
//    do something

});