Cyclic Array Index

cyclicArrayIndex.js

var arr = ['a', 'b', 'c'];

var cyclicArray = function (arr, index) {
    
    var item = ((index % arr.length) + arr.length) % arr.length;
    console.log(arr[item], item);
}

for (var i = -5; i < 5; i++) {
    cyclicArray(arr, i);
}