Carousel slider logic for 3 piece carousel

carousel.js

var marginArray = ['0', '-100%', '-200%'];
        var i = 0;
        jQuery('#prev').click(function() {
            i--;
            i === -1 ? i = 2 : i;
            jQuery('.slider-container').css('margin-left', marginArray[i]);
        });

        jQuery('#next').click(function() {
            i++;
            i === 3 ? i = 0 : i;
            jQuery('.slider-container').css('margin-left', marginArray[i]);
        });