I try to make a game but in following code I have defined a function with a for-loop wherein I puted an switch-statement. Now I see with console.log() that all worked fine but the switch-statement is not working, even if compX and compY both are for example above 2, he doesn´t run the code in that case-statement of switch. I have tested that with console.log() where I asked in that case-statement for ´rux´and ´ruy´, but nothing appeared in the console. So has someone an idea what I am doing wrong? and has maybe someone an example how it does work? Thank you all for every tiny answer!
function updatePosition() {
for (var pc = policeNum; pc > 0; pc--) {
policeRef.child(pc).once('value', function (snapshot) {
var oldData = snapshot.val();
//KI:
var compX = newX - oldData.X;
var compY = newY - oldData.Y;
console.log('We found X:', compX);
console.log('We found Y:', compY);
switch (compX, compY) {
case compX < -2 && compY < -2: //links und oben
var lox = oldData.X - pixelWidth;
var loy = oldData.Y - pixelHeight;
policeRef.child(pc).update({
X: lox,
Y: loy
});
break;
case compX > 2 && compY < -2: //rechts und oben
var rox = oldData.X + pixelWidth;
var roy = oldData.Y - pixelHeight;
policeRef.child(pc).update({
X: rox,
Y: roy
});
break;
case compX < -2 && compY > 2: //links und unten
var lux = oldData.X - pixelWidth;
var luy = oldData.Y + pixelHeight;
policeRef.child(pc).update({
X: lux,
Y: luy
});
break;
case compX > 2 && compY > 2: //rechts und unten
var rux = oldData.X + pixelWidth;
var ruy = oldData.Y + pixelHeight;
console.log('We found rux:', rux);
console.log('We found ruy:', ruy);
policeRef.child(pc).update({
X: rux,
Y: ruy
});
break;
case compX > -2 && compX < 2 && compY > 2: //unten
var uy = oldData.Y + pixelHeight;
console.log('We found uy:', uy);
policeRef.child(pc).update({
Y: uy
});
break;
case compX > -2 && compX < 2 && compY < -2: //oben
var oy = oldData.Y - pixelHeight;
policeRef.child(pc).update({
Y: oy
});
break;
case compY > -2 && compY < 2 && compX > 2: //rechts
var rx = oldData.X + pixelWidth;
policeRef.child(pc).update({
X: rx
});
break;
case compY > -2 && compY < 2 && compX < 2: //links
var lx = oldData.X - pixelWidth;
policeRef.child(pc).update({
X: lx
});
break;
}
context.clearRect(oldData.Y, oldData.X, pixelHeight, pixelWidth)
});
updateDraw();
}
}
You are trying to use switch
as if it is an if-else
statement. You cannot use multiple variables in a switch, nor can it perform any comparison other than ==
.
The syntax for switch
is:
switch(expression) {
case expected_value: // i.e, expression == expected_value
...
break;
case another_expected_value:
...
break;
}
You should change your code to use if-else
instead, e.g.:
if (compX < -2 && compY < -2) {
...
} else if (compX > 2 && compY <-2) {
...
} else {
...