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PHP count_chars() Function

< PHP String Reference

Example

Return a string with all the different characters used in "Hello World!" (mode 3):

<?php
$str = "Hello World!";
echo count_chars($str,3);
?>
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Definition and Usage

The count_chars() function returns information about characters used in a string (for example, how many times an ASCII character occurs in a string, or which characters that have been used or not been used in a string).


Syntax

count_chars(string,mode)

Parameter Description
string Required. The string to be checked
mode Optional. Specifies the return modes. 0 is default. The different return modes are:
  • 0 - an array with the ASCII value as key and number of occurrences as value
  • 1 - an array with the ASCII value as key and number of occurrences as value, only lists occurrences greater than zero
  • 2 - an array with the ASCII value as key and number of occurrences as value, only lists occurrences equal to zero are listed
  • 3 - a string with all the different characters used
  • 4 - a string with all the unused characters

Technical Details

Return Value: Depending on the specified mode parameter
PHP Version: 4+

More Examples

Example 1

Return a string with all the unused characters in "Hello World!" (mode 4):

<?php
$str = "Hello World!";
echo count_chars($str,4);
?>
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Example 2

In this example we will use count_chars() with mode 1 to check the string. Mode 1 will return an array with the ASCII value as key and how many times it occurred as value:

<?php
$str = "Hello World!";
print_r(count_chars($str,1));
?>
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Example 3

Another example of counting how many times an ASCII character occurs in a string: 

<?php
$str = "PHP is pretty fun!!";
$strArray = count_chars($str,1);

foreach ($strArray as $key=>$value)
  {
echo "The character <b>'".chr($key)."'</b> was found $value time(s)<br>";
  }
?>
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< PHP String Reference