JavaScript My image carousel loops correctly on the using the forward arrow but incorrectly on the back arrow. Help!

[Edrol97]

Hi all, code below. Essentially the image carousel adds an extra blank slot when going back in the slideshow which I want to get rid of. I attach my JS

let slides=[];
let lightbox = [];
let counter=0;
let totalimages=0;
function NextImage(){
    for (let i=0;i<totalimages;i++){
        slides[i].style.display="none";
    }
    counter=counter+1;
    if (counter > (totalimages-1)){
        counter=0;
    }
    slides[counter].style.display="block";
}
function PreviousImage(){
    for (let i=0;i<totalimages;i++){
      slides[i].style.display="none";
    }
    counter=counter-1;
    if (counter < 1){
      counter=totalimages;
    }
    slides[counter].style.display="block";
}

As always very grateful for help.

 

[JosiahMaybe]

If you want all slides displayed, counter < 0, counter=totalimages-1, both in previous slide function. You are incrementing totalimages with adding images? Have you considered using like slides.length? There should be error handling for if there are no slides maybe because no index will be valid. X E.

 

[Edrol97]

If you want all slides displayed, counter < 0, counter=totalimages-1, both in previous slide function. You are incrementing totalimages with adding images? Have you considered using like slides.length? There should be error handling for if there are no slides maybe because no index will be valid. X E.

Thank you. This really helped.

 

[JosiahMaybe]

You are welcome. X E.