PHP count_chars() Function - Tutorial Republic
Topic: PHP String ReferencePrev|Next
Description
The count_chars() function counts the number of occurrences of an ASCII character (0..255) in a string and returns it in various ways depending on the mode.
The following table summarizes the technical details of this function.
| Return Value: | Depending on the specified mode parameter. |
|---|---|
| Version: | PHP 4+ |
Syntax
The basic syntax of the count_chars() function is given with:
count_chars(string, mode);
The following example shows the count_chars() function in action.
<?php
// Sample string
$str = "Hello World!";
// Counting unique characters in the string
$arr = count_chars($str, 1);
// Iterating through returned array
foreach($arr as $i => $val){
echo "The character \"" . chr($i) . "\" occurs $val times the string.\n";
}
?>Parameters
The count_chars() function accepts the following parameters.
| Parameter | Description |
|---|---|
| string | Required. Specifies the string to be examined. |
| mode |
Optional. Specifies the return modes. Default is 0. The different return modes are:
|
More Examples
Here're some more examples showing how count_chars() function actually works:
In the following example a string containing all the unique characters in the given string is returned.
<?php
// Sample string
$str = "Hello World!";
// Getting all unique characters in the string
echo count_chars($str, 3);
?>In the following example an array with the ASCII values as keys, and their frequency, i.e. how many times they occurs inside the given string as values, will be returned.
<?php
// Sample string
$str = "Hello World!";
// Getting frequency of characters in the string
print_r(count_chars($str, 1));
?>In the following example a string containing all not used ASCII characters in the string is returned.
<?php
// Sample string
$str = "Hello World!";
// Getting all unused characters in the string
echo count_chars($str, 4);
?>