1  public class CountLettersInArray {
  2    /** Main method */
  3    public static void main(String[] args) {
  4      // Declare and create an array
  5      char[] chars = createArray();
  6  
  7      // Display the array
  8      System.out.println("The lowercase letters are:");
  9      displayArray(chars);
 10  
 11      // Count the occurrences of each letter
 12      int[] counts = countLetters(chars);
 13  
 14      // Display counts
 15      System.out.println();
 16      System.out.println("The occurrences of each letter are:");
 17      displayCounts(counts);
 18    }
 19  
 20    /** Create an array of characters */
 21    public static char[] createArray() {
 22      // Declare an array of characters and create it
 23      char[] chars = new char[100];
 24  
 25      // Create lowercase letters randomly and assign
 26      // them to the array
 27      for (int i = 0; i < chars.length; i++)
 28        chars[i] = RandomCharacter.getRandomLowerCaseLetter();
 29  
 30      // Return the array
 31      return chars;
 32    }
 33  
 34    /** Display the array of characters */
 35    public static void displayArray(char[] chars) {
 36      // Display the characters in the array 20 on each line
 37      for (int i = 0; i < chars.length; i++) {
 38        if ((i + 1) % 20 == 0)
 39          System.out.println(chars[i]);
 40        else
 41          System.out.print(chars[i] + " ");
 42      }
 43    }
 44  
 45    /** Count the occurrences of each letter */
 46    public static int[] countLetters(char[] chars) {
 47      // Declare and create an array of 26 int
 48      int[] counts = new int[26];
 49  
 50      // For each lowercase letter in the array, count it
 51      for (int i = 0; i < chars.length; i++)
 52        counts[chars[i] - 'a']++;
 53  
 54      return counts;
 55    }
 56  
 57    /** Display counts */
 58    public static void displayCounts(int[] counts) {
 59      for (int i = 0; i < counts.length; i++) {
 60        if ((i + 1) % 10 == 0)
 61          System.out.println(counts[i] + " " + (char)(i + 'a'));
 62        else
 63          System.out.print(counts[i] + " " + (char)(i + 'a') + " ");
 64      }
 65    }
 66  }