Java Intermediate: 6/27/2021

Main.java

package com.javafx.test;
import java.util.Scanner;
public class Main {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter a word: ");
        String word = scanner.nextLine().trim().toLowerCase();
        palindrome(word);
        System.out.print("Enter a sentence: ");
        String str = scanner.nextLine();
        wordReverse(str);
        System.out.print("Enter a string: ");
        String str1 = scanner.nextLine();
        System.out.print("Enter a number of times to concacenate it: ");
        int int1 = scanner.nextInt();
        String resultV1 = repeat_str(str1, int1);
        System.out.println("\nAfter repeating "+int1+" times: "+resultV1);

    }
    public static void power(){
        // create a 5x4 array
        int[][] array = new int[5][4];

        for (int power = 2; power < 7; power++) {
            for (int base = 2; base < 6; base++) {
                // assign the correct element based on the pattern
                array[power - 2][base - 2] = (int) (Math.pow(base, power));

                // print the current element
                System.out.print(array[power - 2][base - 2] + "\t\t");
            }
            System.out.println(); // move to next row
        }
    }
    public static void wordReverse(String str){
        String[] words = str.split(" ");
        String reversedString = "";
        for (int i = 0; i < words.length; i++)
        {
            String word = words[i];
            String reverseWord = "";
            for (int j = word.length()-1; j >= 0; j--)
            {
                /* The charAt() function returns the character
                 * at the given position in a string
                 */
                reverseWord = reverseWord + word.charAt(j);
            }
            reversedString = reversedString + reverseWord + " ";
        }
        System.out.println(reversedString);
    }
    public static void palindrome(String word){
        int low = 0; // low index of the word
        int high = word.length() - 1; // high index of the word
        boolean isPalindrome = true;

        if (word.isEmpty()) {
            isPalindrome = false;
        } else {
            while (low < high) {
                // check if chars at low and high indices are matching
                if (word.charAt(low) != word.charAt(high)) {
                    isPalindrome = false;
                    break;
                }
                low++;
                high--;
            }
        }

        if (isPalindrome) {
            System.out.println("The word is a palindrome.");
        } else {
            System.out.println("The word is NOT a palindrome.");
        }
    }
    public static String repeat_str(String str1, int n) {
        if (str1 == null || str1.isEmpty()) {
            return "";
        }
        if (n <= 0) {
            return str1;
        }
        String newString = "";
        for(int i = 1; i <= n; i++){
             newString = newString + str1;
        }

        return newString;
    }

}