1D Arrays

An array is a linear data structure that stores elements of the same data type in contiguous memory locations. It is the simplest and most widely used data structure.

Properties of Arrays

• Contiguous Memory: Array elements are stored right next to each other.
• Fixed Size: In Java, once initialized, the size of an array cannot change.
• Index Based: Elements are accessed via their integer index starting at 0.

Memory Layout

(Indices: [0] -> 10, [1] -> 20, [2] -> 30, [3] -> 40, [4] -> 50)

Operations & Time Complexity

Operation	Best Case	Worst Case (Time)	Description
Access	O(1)	O(1)	Accessing via arr[index]
Search	O(1)	O(n)	Linear search through elements
Insert	O(1)	O(n)	Inserting at end O(1), shifting elements O(n)
Delete	O(1)	O(n)	Removing at end O(1), shifting elements O(n)

Implementation in Java

public class ArrayExample {
    public static void main(String[] args) {
        // Declaration and Initialization
        int[] numbers = new int[5]; // Array of size 5
        
        // Insertion (O(1))
        numbers[0] = 10;
        numbers[1] = 20;
        numbers[2] = 30;
        
        // Literal Initialization
        int[] moreNumbers = {10, 20, 30, 40, 50};

        // Traversal (O(n))
        for (int i = 0; i < moreNumbers.length; i++) {
            System.out.println("Element at index " + i + ": " + moreNumbers[i]);
        }
    }
}