From Zero to Hero: Java Coding Interview Questions Explained

🔰 Beginner-Level Java Coding Questions :

1. Reverse a String :

🔹 Problem:

Given a string, reverse it.

✅ Java Code:

public class ReverseString {
    public static String reverse(String input) {
        StringBuilder reversed = new StringBuilder(input);
        return reversed.reverse().toString();
    }

    public static void main(String[] args) {
        System.out.println(reverse("hello"));  // Output: olleh
    }
}

💡 Explanation:

• StringBuilder is used for its reverse() method.
• Time Complexity: O(n)

2. Check if a String is a Palindrome :

🔹 Problem:

Return true if the string reads the same forward and backward.

✅ Java Code:

public class PalindromeCheck {
    public static boolean isPalindrome(String input) {
        int left = 0, right = input.length() - 1;
        while (left < right) {
            if (input.charAt(left++) != input.charAt(right--)) {
                return false;
            }
        }
        return true…