How to convert string to string array in php

In PHP development, converting a string into a string array is a very basic operation. When we need to split the contents of a string into multiple strings according to specified rules, we need to use the operation of converting the string into a string array.

Now, let us explain in detail how to convert a string into a string array in PHP.

Method 1: Use the str_split() function

PHP provides a built-in function str_split(), which can split a string into a string array of specified length.

Syntax: array str_split ( string $string [, int $split_length = 1 ] )

Parameter description:

string: required, original string. If the specified string is empty, an empty array is returned.

split_length: Optional, the length of the split. The default value is 1. If you want to split according to the specified length, you need to specify the value of this parameter.

Example:

$str = "Hello World";
$arr = str_split($str);
print_r($arr);

Output result:

Array
(
    [0] => H
    [1] => e
    [2] => l
    [3] => l
    [4] => o
    [5] =>  
    [6] => W
    [7] => o
    [8] => r
    [9] => l
    [10] => d
)

Method 2: Use the explode() function

PHP provides a built-in function explode(), which can Split a string into an array of strings according to the specified delimiter.

Syntax: array explode (string $delimiter, string $string [, int $limit = PHP_INT_MAX])

Parameter description:

delimiter: required, delimiter. If you want to split by spaces, specify the value of this parameter as spaces.

string: required, original string. If the specified string is empty, an empty array is returned.

limit: Optional, limit the number of strings. The default value is PHP_INT_MAX. If you want to limit the number of strings, you need to specify a value for this parameter.

Example:

$str = "I love PHP language";
$arr = explode(" ", $str);
print_r($arr);

Output result:

Array
(
    [0] => I
    [1] => love
    [2] => PHP
    [3] => language
)

It should be noted that if the specified delimiter does not exist in the string, the explode() function will return the entire String and array with only one element.

Method 3: Use preg_split() function

PHP provides a built-in function preg_split(), which can split a string into a string array according to the specified regular expression.

Syntax: array preg_split ( string $pattern , string $subject [, int $limit = -1 [, int $flags = 0 ]] )

Parameter description:

pattern: required, regular expression. If you want to split by spaces, specify the value of this parameter as /\s /.

subject: required, original string. If the specified string is empty, an empty array is returned.

limit: Optional, limit the number of strings. The default value is -1. If you want to limit the number of strings, you need to specify a value for this parameter.

flags: Optional, flag parameters. Used to control how regular expressions are matched.

Example:

$str = "I love PHP language";
$arr = preg_split("/\s+/", $str);
print_r($arr);

Output result:

Array
(
    [0] => I
    [1] => love
    [2] => PHP
    [3] => language
)

It should be noted that the performance of the preg_split() function is slightly worse than the other two functions because it requires Regular expression matching.

Summary

The above three methods can convert a string into a string array. When choosing which method to use, you should decide based on actual needs. If you just want to simply split the string according to the specified length, use the str_split() function; if you need to split according to the specified delimiter, use the explode() function; if you need to split according to the regular expression, Then use the preg_split() function.

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