Example: Character Frequency Counter in Java

// Character Frequency Counter
import java.util.HashMap;
import java.util.Map; // Import Map interface for type hinting

// Main class containing the entry point of the program
public class Main {
    public static void main(String[] args) {
        // Step 1: Define the input string
        String inputString = "programming language";

        // Step 2: Create a HashMap to store character frequencies
        Map<Character, Integer> charFrequencies = new HashMap<>();

        // Step 3: Iterate through each character of the string
        for (char ch : inputString.toCharArray()) {
            // Step 4: Check if the character is already in the map
            if (charFrequencies.containsKey(ch)) {
                // If yes, increment its count
                charFrequencies.put(ch, charFrequencies.get(ch) + 1);
            } else {
                // If no, add it to the map with a count of 1
                charFrequencies.put(ch, 1);
            }
        }

        // Step 5: Print the character frequencies
        System.out.println("Character frequencies in \"" + inputString + "\":");
        for (Map.Entry<Character, Integer> entry : charFrequencies.entrySet()) {
            System.out.println("'" + entry.getKey() + "': " + entry.getValue());
        }
    }
}