why did we use collections and state the reason?

Question

Accepted Answer

Collections are used to store and manipulate groups of objects in memory.

Accepted Answer

Collection is Dynamic data type we dont need to specify the size at compile time, It will get grow how user insert data.

Lets take example and explain this topic.

suppose if we declare array

int[] arr = new int[size]; // size is mandetory

suppose we declare collection class : we have different type of collection lets take example of List

List a =new List;

a intiger size is 0 untill first element added into the List a.

It will grow size like 4 --> 8--->16 soo on

once we insert first element the size of List becomes 4, untill adding of 5 th element into a size will not grow.

above technique ll save the memeory usage.

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