How to use the count_chars function in php

Usage of count_chars function in php: [count_chars(string,mode)]. The count_chars function is used to return information about the characters used in a string, such as [count_chars($str,3)].

php The count_chars function returns a string that contains all the different characters used in the string. Its syntax is count_chars(string,mode), parameter string Required, specifies the string to be checked.

(Recommended tutorial: php video tutorial)

How to use the php count_chars function?

Function: Returns a string containing all different characters used in the string.

Syntax:

count_chars(string,mode)

Parameters:

string Required. Specifies the string to check.

mode Optional. Specifies the return mode. The default is 0.

The following are different return modes:

0 - Array, the ASCII value is the key name, the number of occurrences is the key value,

1 - Array, the ASCII value is the key name, the number of occurrences is the key value, only the values ​​whose occurrence number is greater than 0 are listed,

2 - Array, the ASCII value is the key name, the number of occurrences is the key value, only the values ​​are listed A value with an occurrence count equal to 0,

3 - a string with all used distinct characters,

4 - a string with all unused distinct characters .

Description: Return information about the characters used in the string

php count_chars() function usage example 1

<?php
//使用模式3输出
$str = "Hello php.cn!";
echo count_chars($str,3);
?>

Output:

!.Hcehlnop

php count_chars() function usage example 2

<?php
//使用模式1的数组形式输出
$str = "Hello php.cn!";
print_r(count_chars($str,1)) ;
?>

Output:

Array ( [32] => 1 [33] => 1 [46] => 1 [72] => 1 [99] => 1 [101] => 1 [104] => 1 [108] => 2 [110] => 1 [111] => 1 [112] => 2 )

The above is the detailed content of How to use the count_chars function in php. For more information, please follow other related articles on the PHP Chinese website!