Array-1

Q1. Given an array of integers {2, 6, -5, -1, 0, 4, -9}, print only the positive values present in the array.
public class PositiveValues {

    public static void main(String[] args) {
        int[] arr = {2, 6, -5, -1, 0, 4, -9};

        System.out.print("Positive values in the array: ");
        for (int i = 0; i < arr.length; i++) {
            if (arr[i] > 0) {
                System.out.print(arr[i] + " ");
            }
        }
    }
}

Q2. Convert the list of Strings {“ab”, “bc”, “cd”, “de”, “ef”, “fg”, “gh”} into an array of strings and print all
strings stored on odd indices of the array.
import java.util.List;
import java.util.Arrays;

public class OddIndexStrings {

    public static void main(String[] args) {
        List<String> stringList = Arrays.asList("ab", "bc", "cd", "de", "ef", "fg", "gh");
        String[] stringArray = stringList.toArray(new String[0]);

        System.out.print("Strings stored on odd indices of the array: ");
        for (int i = 1; i < stringArray.length; i += 2) {
            System.out.print(stringArray[i] + " ");
        }
    }
}

Q3. Traverse over the elements of the array {1,2,3,4,5,6,7,8} using for each loop and print all even
elements.
public class EvenElements {

    public static void main(String[] args) {
        int[] arr = {1, 2, 3, 4, 5, 6, 7, 8};

        System.out.print("Even elements in the array: ");
        for (int num : arr) {
            if (num % 2 == 0) {
                System.out.print(num + " ");
            }
        }
    }
}
Q4. Calculate the minimum element in the array {2, -3, 5, 8, 1, 0, -4} using standard library method
for calculating the minimum element.
import java.util.Arrays;

public class MinElement {

    public static void main(String[] args) {
        int[] arr = {2, -3, 5, 8, 1, 0, -4};

        int min = Arrays.stream(arr).min().getAsInt();
        System.out.println("Minimum element in the array: " + min);
    }
}
Q5. Find the first peak element in the array {1, 1, 3, 4, 2, 3, 5, 7, 0}
Peak element is the one which is greater than its immediate left neighbor and its immediate right neighbor.
Leftmost and rightmost element cannot be a peak element.
public class FirstPeakElement {
    public static void main(String[] args) {
        int[] arr = {1, 1, 3, 4, 2, 3, 5, 7, 0};
        int n = arr.length;

        for (int i = 1; i < n - 1; i++) {
            if (arr[i] > arr[i-1] && arr[i] > arr[i+1]) {
                System.out.println("The first peak element is: " + arr[i]);
                return;
            }
        }
        System.out.println("No peak element found in the array.");
    }
}