How to convert string to character array in php

In PHP programming, we often need to convert a string into a character array. Because PHP is a dynamic language, many times we need to process strings, which requires converting strings into character arrays to facilitate operations on each character.

In this article, we will introduce common methods to convert strings to character arrays, as well as some common functions that operate on character arrays.

Method 1: str_split function

The str_split function is a PHP built-in function, which can split a string into an array according to the specified length. When no length is specified, it splits each character of a string into an array.

The following is an example:

$str = "hello, world!";
$arr = str_split($str);
print_r($arr);

The output result is:

Array
(
    [0] => h
    [1] => e
    [2] => l
    [3] => l
    [4] => o
    [5] => ,
    [6] =>
    [7] => w
    [8] => o
    [9] => r
    [10] => l
    [11] => d
    [12] => !
)

Method 2: preg_split function

The preg_split function is a PHP built-in function, which can be used as follows The specified regular expression splits the string into an array. When the null character is specified, it splits each character of a string into an array.

The following is an example:

$str = "hello, world!";
$arr = preg_split('//u', $str, -1, PREG_SPLIT_NO_EMPTY);
print_r($arr);

The output result is:

Array
(
    [0] => h
    [1] => e
    [2] => l
    [3] => l
    [4] => o
    [5] => ,
    [6] =>  
    [7] => w
    [8] => o
    [9] => r
    [10] => l
    [11] => d
    [12] => !
)

Method three: mb_str_split function

mb_str_split function is a PHP built-in function, which is specially used Used to split a multi-byte string into an array according to the specified length.

The following is an example:

$str = "你好，世界！";
$arr = mb_str_split($str);
print_r($arr);

The output result is:

Array
(
    [0] => 你
    [1] => 好
    [2] => ，
    [3] => 世
    [4] => 界
    [5] => ！
)

Common operation functions for character arrays

After obtaining the character array, we can Use the following functions to operate on it:

1. implode function: Concatenates the elements of an array into a string.

Example:

$arr = array('hello', ' ', 'world', '!');
$str = implode('', $arr);
echo $str;

Output:

hello world!

2. strlen Function: Returns the length of a string.

Example:

$str = "hello, world!";
$len = strlen($str);
echo $len;

Output:

13

3. strpos Function: Find the first occurrence of a string within another string.

Example:

$str = "hello, world!";
$pos = strpos($str, "world");
echo $pos;

Output:

7

4. substr Function: Returns a substring of a string.

Example:

$str = "hello, world!";
$sub = substr($str, 0, 5);
echo $sub;

Output:

hello

Summary

This article introduces the common methods of converting strings to character arrays in PHP. As well as some common functions that operate on character arrays. These functions can help us perform string processing quickly and efficiently and improve programming efficiency.

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