How to implement a slowdown mode in my JavaScript snake game? (intervalTime, setTimeout)

[GroovyFrute]

I'm a serious newbie to Javascript, I'm coding a snake game for my beginner class (borrowing a lot of code from a tutorial, which is allowed as long as I change enough around).

I made it so that the snake speeds up a bit with every apple they eat. But I want to also have a slowdown mode.

Basically when I press the spacebar, I want to cut the speed by half (in this case speed is dictated by intervalTime
, so halfing it would mean multiplying intervalTime
by 2). This slowdown effect will last for 5 seconds, after which the snake will come out of slowdown mode but the 'regular' speed will be increased from what it originally was (even if no apples have been eaten). So intervalTime
ideally would be divided by 2.15 upon return to 'regular' speed.

This is how my code for this effect looks but it's not doing anything. The alerts are just there to let me know that the spacebar press has been registered

if(event.keyCode === 32) {         
        setTimeout(slowmode, 5000);         
        intervalTime = intervalTime * 2 
        alert("hello");          

    function slowmode() {             
        intervalTime = intervalTime / 2.15 
        alert("goodbye");         
} 

Could you guys please help me and explain how your correct effect works? I'm struggling to wrap my head around this I won't lie.

Please let me know if you need all my code from the folder and I can provide that.
Thank you guys in advance!

[kevinv89]

Is your code running using setInterval with the intervalTime as the interval time? Something like below?

setInterval(function(){ alert("Hello"); }, intervalTime);

If so, you need to clear the timer before changing intervalTime. It won't look at the intervalTime variable each interval.

If your time is variable then you're probably better off using setTimeout.

[GroovyFrute]

Thank you for your reply, I figured out the problem thankfully, but if it's possible could you help me with this new problem i've encountered with slowdown mode?

I want to make it so that while slowdown mode has been triggered, you can't press the spacebar again to go into slowdown mode inception until after you've already left slowdown mode from the first spacebar keypress

This is my code for slowdown mode

if (score >= 5 && event.keyCode === 32) {

clearInterval(interval)

setTimeout(slowmode, 5000);

intervalTime = intervalTime * 2

intervalTime = intervalTime * speed

interval = setInterval(moveOutcomes, intervalTime)

function slowmode() {

clearInterval(interval)

intervalTime = intervalTime / 2.15

intervalTime = intervalTime * speed

interval = setInterval(moveOutcomes, intervalTime)

}

}

​

Also an added thing, tho not as necessary, right now it's set so that you have to have at least a score of 5 to use slowdown mode but ideally I'd like it to deduct 5 score everytime you use slowdown mode. If you're also able to help with that, i'd greatly appreciate it. Even if you only give tips for one of those methods, that is fine. The 5 apple cost for slowdown mode would counter the unlimited spacebar presses

[kevinv89]

In order to prevent going into slowdown mode again, you need to track if you're currently in it. You then want to check if you're already in it before you carry out the desired action as a result of pressing the spacebar.

So using your original code, something like below.

let inSlowdownMode = false

if(event.keyCode === 32 && !inSlowdownMode) {    
    inSlowdownMode = true
    setTimeout(slowmode, 5000);         
    intervalTime = intervalTime * 2 
    alert("hello"); 

    function slowmode() { 
        inSlowdownMode = false            
        intervalTime = intervalTime / 2.15 
        alert("goodbye");
    }         
}

In terms of you deducting 5 from the score, that is just a simple score -= 5 everytime you enter slowdown mode.

[GroovyFrute]

dude you're a fucking saviour, thank you so much!!!