Word Frequency Counter in Java: Explanation & Practice

Problem summary

Write a program that counts how many times each word appears in a sentence.

Starter code

import java.util.*;

public class Main {
    public static void main(String[] args) {
        String sentence = "the quick brown fox jumps over the lazy dog the"; // Test case 1
        
        // Count word frequencies
        // Print each word and count (alphabetical order)
    }
}

Expected output and test cases

• Word frequencies

  brown: 1
  dog: 1
  fox: 1
  jumps: 1
  lazy: 1
  over: 1
  quick: 1
  the: 3

• Simple frequencies

  a: 3
  b: 2
  c: 1

• Same word repeated

  hello: 5

Hints

1. Use HashMap<String, Integer>
2. getOrDefault() for counting
3. Sort keys for output

Related Collections exercises

• Practice Queue Operations in Java
• Practice Stack Operations in Java
• Practice Remove Duplicates from List in Java

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