Скачать или смотреть Code4 Char Count in a String using HashMap(27/01/2025)

Here’s an explanation of the important methods used in the code:

1. toLowerCase()
Purpose: Converts all characters in the string name to lowercase to ensure case insensitivity. For example, "AaBb" would become "aabb".
2. toCharArray()
Purpose: Converts the string name into a character array. This makes it easier to iterate over each character individually.
3. HashMap.put()
Purpose: Inserts key-value pairs into the HashMap.
In this case, the key is a character (c), and the value is its count.
If the character already exists in the map, the value is updated by incrementing it by 1.
4. getOrDefault()
Purpose: Fetches the value associated with a key (character) in the HashMap.
If the key doesn’t exist, it returns the specified default value (0 in this case).
This ensures that the character count starts from 0 for new characters.
5. keySet()
Purpose: Returns a set of all keys (unique characters) in the HashMap.
This is used to iterate over the characters and retrieve their counts.