Skip to content
C

Array Programs

Array-based problems are common in interviews and help build a strong understanding of indexing, traversal, and basic algorithms like searching and sorting.

Why practice these?

Array-based problems are common in interviews and help build a strong understanding of indexing, traversal, and basic algorithms like searching and sorting.

Program 1: Find the Largest Element in an Array

java
public class LargestElement {
    public static void main(String[] args) {
        int[] numbers = {12, 45, 7, 89, 34};
        int largest = numbers[0];

        for (int num : numbers) {
            if (num > largest) {
                largest = num;
            }
        }
        System.out.println("Largest element: " + largest);
    }
}

Output:

Largest element: 89

Program 2: Reverse an Array

java
public class ReverseArray {
    public static void main(String[] args) {
        int[] numbers = {1, 2, 3, 4, 5};

        for (int i = numbers.length - 1; i >= 0; i--) {
            System.out.print(numbers[i] + " ");
        }
    }
}

Output:

5 4 3 2 1

Program 3: Sum of Array Elements

java
public class ArraySum {
    public static void main(String[] args) {
        int[] numbers = {10, 20, 30, 40};
        int sum = 0;

        for (int num : numbers) {
            sum += num;
        }
        System.out.println("Sum: " + sum);
    }
}

Output:

Sum: 100

Key Points to Remember

  • Enhanced for-each loops (for (int num : array)) are convenient for simply reading through array elements.
  • Array-based problems (finding max/min, reversing, sorting) are extremely common in coding interviews.
  • Always be careful with index boundaries to avoid ArrayIndexOutOfBoundsException.