Merging sorted 1st half and 2nd half

Q: Given an integer array of which both first half and second half are sorted. Write a function to merge the two parts to create one single sorted array in place [do not use any extra space]. e.g. If input array is [1,3,6,8,-5,-2,3,8] It should be converted to: [-5,-2,1,3,3,6,8,8]

The idea is to Insert all elements of second half into first half., like we do in Insertion Sort.

we need to keep the arrays sorted while we doing the swaps