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Java

Posted by SZE SZE XU
SZE SZE XU
9,759 Points

how to reverse a particular string in a sentence based on user input

for example, if the user put <hello world 1> it will return hello dlorw , so how to break the sentence? thanks

Sue Dough
Sue Dough
35,800 Points

http://stackoverflow.com/questions/2441501/reverse-each-individual-word-of-hello-world-string-with-java

1 Answer

jcorum
jcorum
71,830 Points

Sue's link to StackOverflow is interesting. But as far as I can see the solutions there reverse all the words in a String, not just the one the users indicate they want reversed.

Here's one way -- as always, there are other ways to do this:

import java.util.Scanner;

class ReverseWordInString {
   public static void main(String[] args) {
      Scanner in = new Scanner(System.in);
      System.out.println("Enter words, space separated, followed by the number ");
      System.out.print("of the word you want reversed (starting with 0): ");
      String string = in.nextLine();
      //String string = "hello world 1";  //use if you don't want Scanner
      //String string = "now is the time for all good men 3";   //2nd test case

      reverseWord(string);
   }

   public static void reverseWord(String s) {
      String[] words = s.split(" ");
      int toReverse = Integer.parseInt(words[words.length - 1]);  //get index of word to reverse
      for (int i = 0; i < words.length; i++) {
         if (i == toReverse)  {  
            System.out.print(new StringBuilder(words[toReverse]).reverse().toString() + " ");
         } else if (i == words.length - 1) {
            //ignore
         } else {
            System.out.print(words[i] + " ");
         }
      }       
   }

}

Note: I would strongly suggest that you not have the user indicate the word they want reversed as part of the input String, but rather as separate input.

Sue Dough
Sue Dough
35,800 Points

Your correct. I am no Java expert however left it there because it could point them in the right direction. I figured they could isolate that 1 word somehow and then do it. It seems like you figured that part out. Nice work.