count_chars

Description

Counts the number of occurrences of every byte-value (0..255) in string and returns it in various ways. The optional parameter mode defaults to 0. Depending on mode count_chars() returns one of the following:

• 0 - an array with the byte-value as key and the frequency of every byte as value.

• 1 - same as 0 but only byte-values with a frequency greater than zero are listed.

• 2 - same as 0 but only byte-values with a frequency equal to zero are listed.

• 3 - a string containing all used byte-values is returned.

• 4 - a string containing all not used byte-values is returned.

Example 1. count_chars() example <?php $data = "Two Ts and one F."; foreach (count_chars($data, 1) as $i => $val) {    echo "There were $val instance(s) of \"" , chr($i) , "\" in the string.\n"; } ?> The above example will output: There were 4 instance(s) of " " in the string. There were 1 instance(s) of "." in the string. There were 1 instance(s) of "F" in the string. There were 2 instance(s) of "T" in the string. There were 1 instance(s) of "a" in the string. There were 1 instance(s) of "d" in the string. There were 1 instance(s) of "e" in the string. There were 2 instance(s) of "n" in the string. There were 2 instance(s) of "o" in the string. There were 1 instance(s) of "s" in the string. There were 1 instance(s) of "w" in the string.

See also strpos() and substr_count().