Can anybody tell me what is wrong with the code??

Question

window.onload = function() {
canv = document.getElementById("gc");
ctx = canv.getContext("2d");
document.addEventListener("keydown", keyPush);
setInterval(game, 1000/15);
}
px = py = 10;
gs = tc = 20;
ax = ay = 15
xv = yv = 0;
trail = [];
tail = 5;
function game() {
px += xv;
py += yv;
if (px < 0) {
px = tc - 1;
}
if (px > tc - 1) {
px = 0;
}
if (py < 0) {
py = tc - 1;
}
if (py > tc - 1) {
py = 0;
}
ctx.fillStyle = "black";
ctx.fillRect(0, 0, canv.width, canv.height);

ctx.fillStyle = "lime";
for (i = 0; i < trail.length; i++) {
ctx.fillRect(trail[i].x*gs, trail[i].y*gs, gs - 2, gs - 2);
if (trail[i].x == px && trail[i].y == py) {
tail = 5;
}
}
trail.push({x: px, y: py});
while(trail.length>tail) {
trail.shift();
}
if (ax == px && ay == py) {
tail++;
ax = Math.floor(Math.random() * tc);
ay = Math.floor(Math.random() * tc);
}
ctx.fillRect(ax * gs, ay * gs, gs - 2, gs - 2);

ctx.fillStyle = "red";
ctx.fillRect(ax * gs, ay * gs, gs - 2, gs - 2);
}
function keyPush(evt) {
switch(evt.keyCode) {
case 37:
xv = 0;yv = 0;
break;
case 38:
xv = 0;yv = -1;
break;
case 39:
xv = 1;yv = 0;
break;
case 40:
xv = 0;yv = 1;
break;
}
}

Now, my question:
Why are every arrow keys working except the left arrow key??

Answer 1

Your code does nothing on left arrow key clicked:

case 37:
xv = 0;yv = 0;
break;

Im pretty sure it was supposed to be

case 37:
xv = -1;yv = 0;
break;

Answer 2

Aleksei Radchenkov

Thank you

Answer 3

Hey you can play with my code:
https://code.sololearn.com/WhoX2669CunV/?ref=app

Answer 4

Aleksei Radchenkov

Thank you for liking the game..