Php calculates the code of which character appears the most frequently for a string of unknown length

In php, the function is used to calculate which character of the unknown length appears the most frequently:
Str_split: splits the string into arrays. A similar function explode () splits strings into arrays. Array_count_values: used to count the number of occurrences of all values in the array.
Arsort: sorts arrays in reverse order and maintains the index relationship.
It is mainly used to sort the arrays that are very important to the unit order. $ Str = "asdfgfdas323344 ##\ \ $ fdsdfg * $ ** $ 443563536254fas"; // any length string
The code is as follows:
$ Arr = str_split ($ str );
$ Arr = array_count_values ($ arr );
Arsort ($ arr );
Print_r ($ arr );

Output:
The code is as follows:
Array
(
[$] => 7
[3] => 6
[*] => 6
[4] => 5
[F] => 5
[S] => 4
[D] => 4
[5] => 3
[A] => 3
[6] => 2
[2] => 2
[G] => 2
[#] => 2
)

Method 2:
Functions used:
Array_unique: deletes repeated values in the array. Substr_count: calculates the number of times a substring appears in a string.
The code is as follows:
$ Str = "asdfgfdas323344 ##\ \ $ fdsdfg * $ ** $ 443563536254fas"; // any length string
$ Arr = str_split ($ str );
$ Unique = array_unique ($ arr );
Foreach ($ unique as $ ){
$ Arr2 [$ a] = substr_count ($ str, $ );
}
Arsort ($ arr2 );
Print_r ($ arr2 );