Problem of the Day

Thursday, May 14, 2026

Problem:

The letterWords method is intended to take as parameters an Array of Strings, words, and a String value letter, and return an ArrayList containing only the Strings in words that begin with the specified letter. The Array {"apple", "banana", "carrot", "avocado"}, sent in as an argument along with "a" as the argument for letter would return an ArrayList containing only "apple", "avocado".

A partial listing of the letterWords method is given here.

public static ArrayList<String> letterWords(String[] words, String letter)
{
    ArrayList<String> result = new ArrayList<String>();
    
    /* missing code */
    
    return result;
}

Which of the following could be used to replace /* missing code */ so the method works as intended?

1. 
   

   for (int i = 0; i < words.length; i++)
       if (words[i].substring(i, i + 1).equals(letter))
           result.add(words[i]);

2. 
   

   for (int i = 0; i < words.length; i++)
       if (words[i].substring(0, 1).equals(letter))
           result.add(words[i]);

3. 
   

   for (String word : words)
       if (word.substring(0, 1).equals(letter))
           result.add(word);

1. I only
2. II only
3. III only
4. I and II only
5. II and III only

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