Arrays

egg carton: it has a specific number of slots, and each slot holds one egg. You can’t put a bowling ball in an egg carton, and you can't suddenly make it hold 20 eggs if it was built for 12.

In Java, arrays are zero-indexed. This means the computer starts counting at 0, not 1.

• The 1st item is at index [0].

• The 2nd item is at index [1].

• The 10th item is at index [9].

Key Rules of Arrays

1. Fixed Size: Once you create an array of size 5, it stays size 5 forever.

2. Same Type: You can have an array of integers OR an array of Strings, but you cannot mix them.

3. The .length Property: You can always ask an array how big it is by using arrayName.length.

The Code Example:

public class ArraysDemo {
    public static void main(String[] args) {
        // 1. Declaring and initializing an array (The "Quick" way)
        String[] favoriteFruits = {"Apple", "Banana", "Mango", "Cherry"};

        // 2. Accessing elements using their index [0, 1, 2, 3]
        System.out.println("First fruit in the list: " + favoriteFruits[0]);
        System.out.println("Third fruit in the list: " + favoriteFruits[2]);

        // 3. Changing a value in the array
        favoriteFruits[1] = "Blueberry"; // Banana is now gone!
        System.out.println("Updated second fruit: " + favoriteFruits[1]);

        // 4. Declaring an empty array with a specific size
        int[] scores = new int[3]; // Creates [0, 0, 0]
        scores[0] = 95;
        scores[1] = 88;
        scores[2] = 72;

        // 5. Using a Loop to print all elements (Very common!)
        System.out.println("\n--- All Student Scores ---");
        for (int i = 0; i < scores.length; i++) {
            System.out.println("Score at index " + i + ": " + scores[i]);
        }
        
        // Bonus: The "Enhanced For-Loop" (For-Each)
        System.out.println("\n--- Fast Fruit List ---");
        for (String fruit : favoriteFruits) {
            System.out.println("I love " + fruit);
        }
    }
}

Expected Output:

First fruit in the list: Apple
Third fruit in the list: Mango
Updated second fruit: Blueberry

--- All Student Scores ---
Score at index 0: 95
Score at index 1: 88
Score at index 2: 72

--- Fast Fruit List ---
I love Apple
I love Blueberry
I love Mango
I love Cherry