Can Java Arrays Be Resized Dynamically, and What's the Best Alternative?

Dynamic Array Sizes in Java

When dealing with arrays in Java, it's crucial to determine the appropriate size upfront. But what if the required size is unknown until runtime? Can we dynamically adjust the size of an array?

No, Java arrays have a fixed size once created. To accommodate unknown array sizes, you have two options:

Option 1: Allocate a Larger Array

Allocate an array larger than the anticipated size. This approach avoids the need for resizing and reallocating, but it may introduce unnecessary memory overhead.

Option 2: Use Collections

The Java Collections framework provides more dynamic data structures like ArrayList. ArrayList wraps an array and automatically grows as needed.

Implementation with ArrayList

List<XClass> myClass = new ArrayList<>();
myClass.add(new XClass());
myClass.add(new XClass());

Benefits of ArrayList over Arrays

• Avoids resizing: ArrayList handles array growth internally.
• Immutability: The ArrayList returned by getItems() is immutable, preventing data modification by callers. This ensures data integrity.
• Type safety: Collections enforce generic type safety, preventing the addition of incompatible objects.

In conclusion, while dynamic array resizing is not possible in Java, ArrayList provides a flexible alternative by automatically adjusting to variable array sizes and enforcing data integrity.

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