As I learnt from the apple documentation that ,In iOS ARC will automatically take care of the memory leaks and memory management.
But my doubt was, do we still need the role of Xcode instruments (Allocations and Leak) to ensure whether memory leak has happened in our application??
Please do share if you know the solution.
Yes, of course you need to use Intruments.
Swift uses Automatic Reference Counting (ARC) to track and manage your app’s memory usage. In most cases, this means that memory management “just works” in Swift, and you do not need to think about memory management yourself. ARC automatically frees up the memory used by class instances when those instances are no longer needed.
However, in a few cases ARC requires more information about the relationships between parts of your code in order to manage memory for you. This chapter describes those situations and shows how you enable ARC to manage all of your app’s memory.
You should take a look over Automated Reference Counting.
One of the most common situation is when you have strong reference cycles between class instances, because the compiler doesn't know when to release that part of memory. Also take a look over the differences of strong and weak references.
But as even Apple saids, "In most cases", you should be ok without, but if your application crashes, it could be that you have memory issues.