Step 2: Counting the Words Using a HashMap

Why a HashMap?

A HashMap provides an efficient way to store key-value pairs. In our case, the word will be the key, and its frequency will be the value. This will enable us to look up the frequency of a word in constant time.

How to Count?

We'll initialize an empty HashMap (or an object in JavaScript, or a dictionary in Python) to store the occurrences of each word. Let's call this HashMap occurrences.

Counting the Words Using a HashMap

Code Snippet for Counting

Here's how you can populate the occurrences HashMap:

1Map<String, Integer> occurrences = new HashMap<>();
2for(String word : split_s) {
3    if(occurrences.containsKey(word)) {
4        occurrences.put(word, occurrences.get(word) + 1);
5    } else {
6        occurrences.put(word, 1);
7    }
8}