php man page for count_chars

COUNT_CHARS(3)								 1							    COUNT_CHARS(3)

count_chars - Return information about characters used in a string

SYNOPSIS
       mixed count_chars (string  $string, [int  $mode])

DESCRIPTION
	Counts the number of occurrences of every byte-value (0..255) in $string and returns it in various ways.

PARAMETERS
	      o $string
		- The examined string.

	      o $mode
		- See return values.

RETURN VALUES
	Depending on $modecount_chars(3) returns one of the following:

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

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

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

	      o 3 - a string containing all unique characters is returned.

	      o 4 - a string containing all not used characters is returned.

EXAMPLES
       Example #1

	      count_chars(3) 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.
";
	      }
	      ?>

	      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(3), substr_count(3).

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