It is a very simple comparison sort to sort an array. A comparison sort compares the current value that we are trying to sort with other values in the array. It works with one item at a time and iteratively places each item in correct place so as to get a required sorted array.
Actually, insertion sort is not as efficient as some advanced algorithms such as heap sort or merge sort. It is not a best option while dealing with large programs. Because of its low hidden constant value, an insertion sort outperforms some of the advanced algorithms such as heap or quick sort while dealing with small arrays.
Insertion sort works by moving from left to right over an array. It will use the current item as a 'key' and searches for a value to the left of that key to find a location where the key should actually resides.
In the following example the array given is 0,-3,5,8,2,7,6
In the same way, at the end of final iteration the sorted array will be -3,0,2,5,6,7,8
<html>
<head>
<script>
function iSort(array) {
for (var p = 1; p < array.length; p++) {
if (array[p] < array[0]){
array.unshift(array.splice(p,1)[0]);
}
else if (array[p] > array[p-1]){
continue;
}
else {
for (var q = 1; q < p; q++) {
if (array[p] > array[q-1] && array[p] < array[q]){
array.splice(q,0,array.splice(p,1)[0]);
}
}
}
}
return array;
}
document.write(iSort([0,-3,5,8,2,7,6]));
</script>
</body>
</html>-3,0,2,5,6,7,8
