HowToDoInJava

Reverse words in string in Java

By Lokesh Gupta | Filed Under: Java String class

Learn to reverse each word in a sentence in Java with example. We will reverse words in string in place using StringBuilder and StringUtils classes.

Original String – how to do in java

Reverse words – woh ot od ni avaj

1. Reverse words in string – StringBuilder class

  • Tokenize each word using String.split() method.
  • Loop through string array and use StringBuilder.reverse() method to reverse each word.
  • Join all revered words to get back string.
String blogName = "how to do in java";
StringBuilder reverseString = new StringBuilder();

String[] words = blogName.split(" ");		//step 1

for (String word : words) 
{
    String reverseWord = new StringBuilder(word).reverse().toString();		//step 2
    reverseString.append(reverseWord + " ");								//step 3
}

System.out.println( reverseString.toString().trim() );		//verify reversed string

Program output.

woh ot od ni avaj

2. Reverse words in string – StringUtils class

StringUtils class is in Apache command lang library. Use it’s StringUtils.reverseDelimited() method to reverse each word and join the string.

String blogName = "how to do in java";

String reverseString = StringUtils.reverseDelimited( StringUtils.reverse(sentence), ' ' );

System.out.println( reverseString );

Program output.

woh ot od ni avaj

In this post, we learned to reverse each word in a sentence in Java.

Happy Learning !!

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About Lokesh Gupta

A family guy with fun loving nature. Love computers, programming and solving everyday problems. Find me on Facebook and Twitter.

Feedback, Discussion and Comments

  1. ismail

    How can I reverse 2 words in a string? For example reverse “Hi John” to “John Hi”.

    Reply

    • Anton

      // this is a little hard coded, you can’t use StringBuilder for this task
      String original = “Hi John”;
      String [] split = original.split(” “);
      String result = split[1] + ” ” + split[0];
      System.out.println(result);

      Reply

  2. Jagannathan

    @Rishab
    was this question is asked in amazon interview?

    Reply

  3. Rishabh Gupta

    How can i reverse word of string without using any inbuilt function?

    Reply

    • Mohan Das

      store it in character array .Overwrite accordance with reversal using INDEX OF CHARACTERS
      Here below is your program:-

      import java.util.Scanner;

public class Reverse
{
	public static void main(String args[])
	{
		Scanner sc=new Scanner(System.in);

		System.out.println("Enter the string:");

		String s = sc.nextLine();

		int l = s.length();

		System.out.println("Length="+l);

		char ch[] = s.toCharArray();

		for(int i=l-1; i>=0; i--)
		{
			System.out.print(ch[i]);
		}
	}
}
      Reply

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