Example: CharacterFrequencyUsingArray in Java

// CharacterFrequencyUsingArray
public class Main {
    public static void main(String[] args) {
        String inputString = "programming";
        
        // Step 1: Initialize an array to store character counts.
        // Assuming ASCII characters (0-255). For full Unicode, a larger array (65536) would be needed.
        int[] charCounts = new int[256]; 

        // Step 2: Iterate through the input string.
        for (int i = 0; i < inputString.length(); i++) {
            char ch = inputString.charAt(i);
            // Step 3: Increment the count for the character at its corresponding ASCII index.
            charCounts[ch]++; 
        }

        // Step 4: Iterate through the charCounts array to print frequencies.
        System.out.println("Character frequencies (using array):");
        for (int i = 0; i < charCounts.length; i++) {
            if (charCounts[i] > 0) {
                // Cast the index back to a char for printing
                System.out.println((char) i + ": " + charCounts[i]);
            }
        }
    }
}