So far, we've looked at using an array when several items need to be grouped together. But arrays weren't enough to fulfill all of our engineering problems. In most cases, we weren't aware of the number of items we want to group together. So, similar to the saying, necessity is the mother of invention, we created a data structure by wrapping an array into a custom class and making it grow able when required. This helped us in grouping multiple items without even knowing their size. We called them Vector or ArrayList. Though our size requirements are solved by ArrayList, we've a basic problem in ArrayList and that is its performance while inserting. If the ArrayList is full and we try to insert an item, we need to create a bigger array and copy all existing items to the new one, which might take more time if the size is big. This is...
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