How do you find words in a text file and print the most frequent word shown using array?

Question

I'm having trouble of figuring out how to find the most frequent word and the most frequent case-insensitive word for a program. I have a scanner that reads through the text file and a while loop, but still doesn't know how to implement what I'm trying to find. Do I use a different string function to read and print the word out?

Here is my code as of now:

public class letters {
public static void main(String[] args) throws FileNotFoundException {
    FileInputStream fis = new FileInputStream("input.txt");
    Scanner scanner = new Scanner(fis);
    String word[] = new String[500];
    while (scanner.hasNextLine()) {
        String s = scanner.nextLine();
        for (int i = 0; i < s.length(); i++) {
            char ch = s.charAt(i);
             }

          }
      String []roll = s.split("\\s");
       for(int i=0;i<roll.length;i++){
           String lin = roll[i];
           //System.out.println(lin);
      }
 }

This is what I have so far. I need the output to say:

   Word:
   6 roll

  Case-insensitive word:
  18 roll

And here is my input file:

@
roll tide roll!
Roll Tide Roll!
ROLL TIDE ROLL!
ROll tIDE ROll!
 roll  tide  roll! 
 Roll  Tide  Roll! 
 ROLL  TIDE  ROLL! 
   roll    tide    roll!   
    Roll Tide Roll  !   
@
65-43+21= 43
65.0-43.0+21.0= 43.0
 65 -43 +21 = 43 
 65.0 -43.0 +21.0 = 43.0 
 65 - 43 + 21 = 43 
 65.00 - 43.0 + 21.000 = +0043.0000 
    65   -  43  +   21  =   43  

I just need it to find the most occuring word(Which is the maximal consecutive sequence of letters)(which is roll) and print out how many times it is located(which is 6) . If anybody can help me on this, that would be really great! thanks

Answer 1

Consider using a Map<String,Integer> for the word then you can implement this to count words and will be work for any number of words. See Documentation for Map.

Like this (would require modification for case insensitive)

public Map<String,Integer> words_count = new HashMap<String,Integer>();

//read your line (you will have to determine if this line should be split or is equations
//also just noticed that the trailing '!' would need to be removed

String[] words = line.split("\\s+");
for(int i=0;i<words.length;i++)
{
     String s = words[i];
     if(words_count.ketSet().contains(s))
     {
          Integer count = words_count.get(s) + 1;
          words_count.put(s, count)
     }
     else
          words_count.put(s, 1)

}

Then you have the number of occurrences for each word in the string and to get the most occurring do something like

Integer frequency = null;
String mostFrequent = null;
for(String s : words_count.ketSet())
{
    Integer i = words_count.get(s);
    if(frequency == null)
         frequency = i;
    if(i > frequency)
    {
         frequency = i;
         mostFrequent = s;
    }
}

Then to print

System.out.println("The word "+ mostFrequent +" occurred "+ frequency +" times");