Find repeated words

Question

I have this assignment where need to

Write a method that takes a String parameter. If the String has a double letter (i.e. contains the same letter twice in a row) then it should return true. Otherwise, it should return false.

This method must be named hasRepeat() and have a String parameter. This method must return a boolean.

However, when I check in my code, I am failing some tests.

It says that it isn't returning false when there are no repeated letters.

Here is my code:

public static boolean hasRepeat(String word) {
    for (int i = 0; i < word.length(); i++) {
        for (int j = i + 1; j < word.length(); j++) {
            if (word.substring(i, i + 1).equals(word.substring(i, j))) {
                return true;
            }
        }
    }
    return false;
}

user_2319407 · Answer

There's no need in nested loops. All we have to do is to check if current char equals to previous:

public static boolean hasRepeat(String word) 
{
   // hasRepeat is a public method; we shoud be ready for any input
   if (word == null)
       return false;

   // here we start from 1: there's no previous char for charAt(0)
   for (int i = 1; i < word.length(); ++i)
     if (word.charAt(i - 1) == word.charAt(i))
       return true;

   return false;
}

user_18152805 · Answer

The issue is that when checking the string, the loop skips the last two string, we can fix this by adding the length of the string to 1. Here is the code. What's also different between our code is the substring

Find repeated words

2 Answers