java special for collection size, array size, and string size

Size:
For Collections (eg: Map, List, etc ): usually it use collection.size(),
eg

        Map<Character, Integer> map = new HashMap<>();

        int s1 = map.size();

   

        List<Integer> list = Arrays.asList(a);

    int s2 = list.size();

But For Array, it uses length,

eg

        Integer[] array = new Integer[10];

        int s3 = array.length;

For String, it uses length(),

        String str = "string";

        int s4 = str.length();