Alphabetical Character Frequency in Java: Explanation & Practice

Problem summary

Print each unique character and its frequency in alphabetical order.

Starter code

public class Main {
    public static void main(String[] args) {
        String str = "hello"; // Test case 1
        
        // Print frequency of each character
        // Format: char:count (one per line, sorted)
    }
}

Expected output and test cases

• hello frequencies

  e:1
  h:1
  l:2
  o:1

• abab frequencies

  a:2
  b:2

• aaa frequencies

  a:3

Hints

1. Use int array of size 26 for lowercase
2. Index = char - 'a'
3. Sort alphabetically when printing

Related Strings exercises

• Practice Character Frequency in Java
• Practice String Compression in Java
• Practice Remove Adjacent Duplicates in Java

Practice all Strings exercises · Run this idea in the Java compiler