How to reverse a sentence via Java

In this blog post, I will be demonstrating how you can reverse a sentence via Java. So if the input String is “Hello World”, the program will print “World Hello”.

Consider the following code snippet:

package learnjava.strings;

public class ReverseASentenceDemo {

public static void main(String[] args) {
String inputStr = "This is a test program";
System.out.println("Input String is "+inputStr);
String[] words = inputStr.split(" ");
StringBuffer reversedString = new StringBuffer("");
for(int i = words.length-1; i >= 0; i --){
reversedString.append(words[i]);
if(i != 0)
reversedString.append(" ");
}
System.out.println("Reversed String is "+reversedString.toString());

}

}

In this code, the input String is first split using the String.split method. It is split based on spaces, so it returns an array of words. This array is then traversed in the reverse direction. Each word in the array is appended to a new StringBuffer object. If the current word is not the last word, a space is also added after each word.

So the above code will print the following output:

Input String is This is a test program
Reversed String is program test a is This