Java program to reverse a sentence

Problem

Write a java program to:

• Reverse a sentence by letters
• Reverse a sentence by words

Reverse Sentence by letters

Code

1.  public class Main {
2.      public static void main(String[] args) {
3.          String sentence="Welcome to java";
4.          System.out.println(reverseByLetters(sentence));
5.      }
6.      public static String reverseByLetters(String sentence){
7.          char[] c=sentence.toCharArray();
8.          String out="";
9.          for (int i=c.length-1;i>=0;i--){
10.              out+=c[i];
11.          }
12.          return out;
13.      }
14.  }
15.  

Output

avaj ot emocleW

Explanation

• First, we broke the String sentence into characters by calling the toCharArray() function on the string.
• Then we used a for loop to iterate the characters in reverse and get the final String.

Reverse Sentence by Words

Code

1. public class Main {
2.     public static void main(String[] args) {
3.         String sentence="Welcome to java";
4.         System.out.println(reverseByWords(sentence));
5.     }
6.     public static String reverseByWords(String sentence){
7.         String[] s=sentence.split(" ");
8.         String out="";
9.         for (int i=s.length-1;i>=0;i--){
10.             out+=s[i]+" ";
11.         }
12.         return out;
13.     }
14. }
15.  

Output

java to Welcome 

Explanation

• We broke the sentence at spaces using the string.split(" ") function and stored it in a String array.
• Then we iterated the array in reverse. We kept on attaching each element of the array together along with space and we got the final result.