/*In insertion sort, we divide the initial unsorted array into two parts; * sorted part and unsorted part. Initially the sorted part just has one * element (Array of only 1 element is a sorted array). We then pick up * element one by one from unsorted part; insert into the sorted part at * the correct position and expand sorted part one element at a time. */ function insertionSort(unsortedList) { var len = unsortedList.length; for (var i = 1; i < len; i++) { var tmp = unsortedList[i]; //Copy of the current element. /*Check through the sorted part and compare with the number in tmp. If large, shift the number*/ for (var j = i - 1; j >= 0 && (unsortedList[j] > tmp); j--) { //Shift the number unsortedList[j + 1] = unsortedList[j]; } //Insert the copied number at the correct position //in sorted part. unsortedList[j + 1] = tmp; } } var arr = [5, 3, 1, 2, 4, 8, 3, 8]; insertionSort(arr); console.log(arr);