Arrays in java

1. Introduction to Arrays
• Understanding Arrays with a DVD Box Analogy
• - Arrays store multiple elements of the same
type.
• - Elements are stored in contiguous memory
locations.
• - Arrays provide efficient access to elements
via indexing.

2. Real-Life Analogy: A DVD Box
• A DVD box can hold multiple DVDs, just like an
array can hold multiple items.
• - All DVDs have the same structure, just like
arrays hold elements of the same type.
• - The box has a fixed capacity, similar to an
array’s fixed size in many languages.

3. Creating an Array
• How to Create an Array
• Example Code:
• DVD[] dvdCollection = new DVD[15];
• - Define the array with a specified type and
capacity.
• - Initially, all slots are empty (null for objects,
default values for primitives).

4. Adding Elements to an Array
• Storing DVDs in the Array
• Example Code:
• dvdCollection[0] = new DVD("The Avengers");
• - Arrays use zero-based indexing.
• - Elements can be assigned to specific indices.
• - If an index is overwritten, the previous value
is lost.

5. Accessing Elements in an Array
• Retrieving DVDs from the Collection
• Example Code:
• DVD myMovie = dvdCollection[0];
• - Use an index to retrieve a specific element.
• - Accessing an uninitialized index returns null
or a default value.

6. Array Capacity vs. Length
• Understanding Capacity and Length
• - Capacity: The total size of the array (fixed at
creation).
• - Length: The number of elements currently
stored.
• Example Code:
• int capacity = dvdCollection.length;

7. Array Operations - Inserting
Elements
• Adding Elements to an Array
• - Insert at the end (efficient O(1)).
• - Insert at the beginning (requires shifting,
O(N)).
• - Insert at any index (may require shifting,
O(N)).

8. Array Operations - Deleting
Elements
• Removing Elements from an Array
• - Deleting from the end (fast O(1)).
• - Deleting from the beginning (shifting
required, O(N)).
• - Deleting from any index (shifting required,
O(N)).

9. Searching in an Array
• Finding a DVD in the Collection
• - Linear Search: Check each element
sequentially (O(N)).
• - Binary Search: Efficient search in sorted
arrays (O(log N)).
• Example Linear Search Code:
• for (int i = 0; i < dvdCollection.length; i++) {

10. Summary and Next Steps
• Wrapping Up Arrays
• - Arrays store fixed-size elements of the same
type.
• - Use indexing to access or modify elements.
• - Operations: Insertion, deletion, searching.
• - Next up: Solving LeetCode problems on
Arrays!

11. Array - A DVD Box?
• A DVD box is like an Array:
• - Stores multiple items of the same type
(DVDs).
• - Each DVD has a cover with details like title,
cast, etc.
• - The box has a fixed size, just like an array's
fixed capacity.