When to use array in cpp...?

Answer 1

The use of array is same in most of the language. When u want to store n th value of particular datatype in single variable.
Eg if u want to store the name of students then array will be used .
Explore some stuffs regarding array in yt. U will find something more abt it

Answer 2

When we find that there's a need to have multiple data (of the same type) be stored sequentially in memory, which can be accessed and modified by just specifying the array variable and a desired index. Array use cases are broad subject, but array simplifies data organisation by storing them in sequence, opposed to storing them into various variables.