Question

I have to find the last word in a string and can’t understand why my code isn’t working. This is what I have:

int i, length;
String j, lastWord;
String word = "We the people of the United States in order to form a more perfect union";    
length = word.length();    



for (i = length - 1; i > 0; i--)
{
  j = word.substring(i, i + 1);
  if (j.equals(" ") == true);
  {
    lastWord = word.substring(i);
    System.out.println("Last word: " + lastWord);
    i = -1; //to stop the loop
  }
}

However, when I run it, it prints the last letter. I know I could use

String lastWord = word.substring(word.lastIndexOf(” “) + 1)

But I’m pretty sure my teacher doesn’t want me to do it this way. Any help?

Answer 1

You need to remove the ; after the if to make it work:

if (j.equals(" ")) // <== No semicolon, and no == true
{
    lastWord = word.substring(i);
    System.out.println("Last word: " + lastWord);
    i = -1; //to stop the loop
}

You do not need == true for booleans inside control statements, either.

Finally, making single-character substrings is more expensive than using single characters. Consider using charAt(i) instead:

if (word.charAt(i) == ' ') // Single quotes mean one character
{
    lastWord = word.substring(i+1);
    System.out.println("Last word: " + lastWord);
    break; // there is a better way to stop the loop
}