Arrays

public class ArrayBasics {
    public static void main(String[] args) {
        // Declare and initialize
        String[] browsers = {"Chrome", "Firefox", "Safari", "Edge"};

        // Access by index (0-based)
        System.out.println(browsers[0]);  // Chrome
        System.out.println(browsers[3]);  // Edge

        // Length
        System.out.println("Total: " + browsers.length);  // 4

        // Modify an element
        browsers[2] = "Brave";
        System.out.println(browsers[2]);  // Brave
    }
}

public class ArrayDeclarations {
    public static void main(String[] args) {
        // Method 1: Declare with values
        int[] scores = {85, 92, 78, 96, 88};

        // Method 2: Declare with size, fill later
        String[] testNames = new String[3];
        testNames[0] = "Login Test";
        testNames[1] = "Search Test";
        testNames[2] = "Checkout Test";

        // Method 3: Declare and initialize with new
        double[] prices = new double[]{29.99, 49.99, 99.99};

        // Default values for empty arrays
        int[] nums = new int[3];     // {0, 0, 0}
        boolean[] flags = new boolean[3]; // {false, false, false}
        String[] names = new String[3];   // {null, null, null}

        System.out.println(nums[0]);    // 0
        System.out.println(flags[0]);   // false
        System.out.println(names[0]);   // null
    }
}

import java.util.Arrays;

public class ArrayIteration {
    public static void main(String[] args) {
        int[] scores = {85, 92, 78, 96, 88};

        // for loop
        for (int i = 0; i < scores.length; i++) {
            System.out.println("Test " + (i + 1) + ": " + scores[i]);
        }

        // for-each
        int sum = 0;
        for (int score : scores) {
            sum += score;
        }
        System.out.println("Average: " + (double) sum / scores.length);

        // Print entire array
        System.out.println(Arrays.toString(scores));  // [85, 92, 78, 96, 88]
    }
}

import java.util.Arrays;

public class ArrayOps {
    public static void main(String[] args) {
        int[] scores = {85, 92, 78, 96, 88};

        // Sort
        Arrays.sort(scores);
        System.out.println(Arrays.toString(scores));  // [78, 85, 88, 92, 96]

        // Find max and min (after sorting)
        System.out.println("Min: " + scores[0]);                    // 78
        System.out.println("Max: " + scores[scores.length - 1]);    // 96

        // Search (array must be sorted)
        int index = Arrays.binarySearch(scores, 88);
        System.out.println("88 found at index: " + index);  // 2

        // Copy
        int[] copy = Arrays.copyOf(scores, scores.length);
        System.out.println(Arrays.toString(copy));

        // Fill
        int[] zeros = new int[5];
        Arrays.fill(zeros, -1);
        System.out.println(Arrays.toString(zeros));  // [-1, -1, -1, -1, -1]

        // Compare
        int[] a = {1, 2, 3};
        int[] b = {1, 2, 3};
        System.out.println(Arrays.equals(a, b));  // true
        System.out.println(a == b);               // false — different objects
    }
}

public class FindMax {
    public static void main(String[] args) {
        int[] responseTimes = {230, 150, 890, 420, 310};

        int max = responseTimes[0];
        for (int time : responseTimes) {
            if (time > max) {
                max = time;
            }
        }
        System.out.println("Slowest response: " + max + "ms");  // 890ms
    }
}