How to convert PHP string to array

In PHP development, sometimes we need to convert a string into an array for further operations and processing. In this article, we will introduce how to convert a PHP string to an array.

PHP provides a variety of methods to convert strings into arrays. The choice of specific methods depends on the format and content of the string. Below we discuss common methods.

1. explode function

The explode function is the most common and commonly used method in PHP to convert a string into an array. Its syntax is as follows:

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

Among them, $delimiter represents the delimiter, $string represents the string that needs to be separated, and $limit represents the upper limit of the number of array elements returned.

For example, if we convert the comma-separated string "1,2,3,4,5" into an array, we can use the following code:

$str = "1,2,3,4,5";
$arr = explode(",", $str);
print_r($arr);

The output result is as follows:

Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => 5
)

2. str_split function

The str_split function can split a string into multiple substrings according to the specified length and return an array of these substrings. The syntax of this function is as follows:

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

Among them, $string represents the string that needs to be split, and $split_length represents the length of each substring.

For example, if we split the string "abcdefg" into an array according to each letter, we can use the following code:

$str = "abcdefg";
$arr = str_split($str);
print_r($arr);

The output result is as follows:

Array
(
    [0] => a
    [1] => b
    [2] => c
    [3] => d
    [4] => e
    [5] => f
    [6] => g
)

3. preg_split function

If you need to split a string according to a regular expression, you can use the preg_split function. The syntax of this function is as follows:

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

Among them, $pattern represents the matching pattern of the regular expression, $subject represents the string that needs to be split, $limit represents the upper limit of the number of returned array elements, and $flags represents matching. flag bit.

For example, if we divide the string "1,2,3,a,b,c" into an array according to numbers and letters, we can use the following code:

$str = "1,2,3,a,b,c";
$arr = preg_split("/[, ]/", $str);
print_r($arr);

The output result is as follows :

Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => a
    [4] => b
    [5] => c
)

4. unserialize function

If the string is serialized data, you can use the unserialize function to convert it into an array. The syntax of this function is as follows:

mixed unserialize ( string $str )

Among them, $str represents the string that needs to be deserialized.

For example, we will serialize the data "a:3:{i:0;s:1:"1";i:1;s:1:"2";i:2;s :1:"3";}" to convert to an array, you can use the following code:

$str = 'a:3:{i:0;s:1:"1";i:1;s:1:"2";i:2;s:1:"3";}';
$arr = unserialize($str);
print_r($arr);

The output result is as follows:

Array
(
    [0] => 1
    [1] => 2
    [2] => 3
)

5. json_decode function

If the string is data in JSON format, you can use the json_decode function to convert it to an array. The syntax of this function is as follows:

mixed json_decode ( string $json [, bool $assoc = false [, int $depth = 512 [, int $options = 0 ]]] )

Among them, $json represents the JSON string that needs to be decoded, $assoc represents whether to return an associative array, $depth represents the depth of recursion, and $options represents the decoding options.

For example, if we convert the data in JSON format "{"name":"Jack","age":20,"gender":"male"}" into an array, we can use the following code:

$str = '{"name":"Jack","age":20,"gender":"male"}';
$arr = json_decode($str, true);
print_r($arr);

The output results are as follows:

Array
(
    [name] => Jack
    [age] => 20
    [gender] => male
)

Summary

There are many ways to convert strings to arrays in PHP, including the explode function, str_split function, preg_split function, unserialize function and json_decode function. Developers can choose appropriate methods for data processing based on actual needs to improve development efficiency and code quality.

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