Thread: Simple code error

I am getting an error with this code

 import java.util.Scanner;
 
public class five
{
public static void main(String[] args)
{
 
Scanner keyboard = new Scanner(System.in);
String sentence = "Please enter a line of text. No punctuation please";
 
System.out.print(sentence);
 
String s1, firstWord, firstLetter, endSentence, newSentence;
s1 = keyboard.nextLine();
 
int wordEndLoc = s1.indexOf(' ');
 
//retrieve the first word to be replaced
firstWord = s1.substring(0,wordEndLoc);
 
//get the second part of the sentence without the first word and trim trailing spaces
endSentence = s1.substring(wordEndLoc,s1.length()).trim();
 
//combine the second part with the first word at the end
newSentence = endSentence + " " + firstWord;
 
//retrieve he first letter of the newly organized sentence, and capitalize it as well
firstLetter = newSentence.substring(0,1).toUpperCase();
 
//again, get the second part of the sentence (without the first letter)
endSentence = newSentence.substring(1,s1.length());
 
 
//combine the first letter with the second part
newSentence = firstLetter + endSentence;
String mess2 = "I have replaced that line to read: ";
System.out.print(mess2);
System.out.print(newSentence);
}
}

My output says
Please enter a line of text. No punctuation please
Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: -1
at java.lang.String.substring(Unknown Source)
at five.main(five.java:18)

indexOf returns -1 if the search item was not found, so if what a space isn't found you will see this exception when your code continues to try and parse the string.

Hmm. So what do I need to do to fix this? Im sorry, I am very new at this...Thank you for the reply

Check and make sure the value is not -1

if ( wordEndLoc == -1 ){
// most likely the user entered a single word or just pressed the enter button (the s1 string is empty).
//Deal with each however you wish your program to respond to each.
}