Exercise

Modifying arrays

You are looking at the array of students' grades once again. It has come to your attention that your own grade, which is at index 4 in the array, is not as high as it should be. It's time to write a mutating function to take care of this obvious mistake.

Instructions

100 XP

Write a mutating function named topstudent!(), which takes an array named x as an argument and modifies the value at index 4 to "AAAA".
Use the function to modify the grades array grades_array.