How to replace _ with an array in php

In PHP programming, array is a very useful data type that can be used to store large amounts of data, and it has high flexibility and scalability. When we need to convert some data into an array, we can use some functions to help us. This article will introduce how to use functions in PHP to convert the underscore "_" in a string into an array.

In PHP, there are two functions that can be used to convert the underscore "_" in a string into an array. They are the explode and str_replace functions. Below we will introduce the usage and precautions of these two functions one by one.

1. Use the explode function to convert a string into an array

The explode function in PHP can be used to split a string and return the split string array. We can use the explode function to separate the underscore "_" in the string and store the separated string in an array.

The syntax is as follows:

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

Among them, the $delimiter parameter specifies the delimiter to split the string, the $string parameter is the string to be split, and the $limit parameter specifies the number of array elements to be returned. When used, the $delimiter parameter needs to be set to an underscore "_".

Code example:

$str = "James_Smith_David";
$arr = explode("_", $str);
print_r($arr);

Output result:

Array
(
    [0] => James
    [1] => Smith
    [2] => David
)

Notes:

When using the explode function, you need to pay attention to the following points:

1) If the $limit parameter is set, the number of array elements returned will be affected.

2) If the $delimiter parameter does not exist in $string, the function will return an array containing the entire string.

3) If the $string parameter is an empty string, in PHP 7.1 and above versions of PHP, the explode function will return an empty array.

2. Use the str_replace function to replace the underscores in the string with an array

In addition to using the explode function, we can also use the str_replace function to replace the underscores in the string "_ ” is replaced with an array.

The syntax is as follows:

mixed str_replace ( mixed $search , mixed $replace , mixed $subject [, int &$count ] )

Among them, the $search parameter specifies the string to be searched, the $replace parameter specifies the replacement string, the $subject parameter is the target string, and the $count parameter is used The number of times after storage replacement.

Code example:

$str = "James_Smith_David";
$arr = str_replace("_", ",", $str);
$arr = explode(",", $arr);
print_r($arr);

Output result:

Array
(
    [0] => James
    [1] => Smith
    [2] => David
)

Notes:

When using the str_replace function, you need to pay attention to the following points:

1) The $replace parameter can be an array to replace multiple values ​​in the $subject parameter.

2) If the $subject parameter is an empty string, in PHP 7.1 and above versions of PHP, the str_replace function will return an empty string.

To sum up, we can use one of the above two functions to convert the underscore "_" in the string into an array, which will greatly improve our efficiency in PHP programming. Of course, when using it, we need to choose a suitable function according to specific needs and follow the precautions for using the function to achieve the ideal effect.

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