explode
(PHP 4, PHP 5)
explode — Split a string by string
Description
$delimiter
, string $string
[, int $limit
] )
Returns an array of strings, each of which is a substring of
string formed by splitting it on
boundaries formed by the string delimiter.
Parameters
-
delimiter -
The boundary string.
-
string -
The input string.
-
limit -
If
limitis set and positive, the returned array will contain a maximum oflimitelements with the last element containing the rest ofstring.If the
limitparameter is negative, all components except the last -limitare returned.If the
limitparameter is zero, then this is treated as 1.
Note:
Although implode() can, for historical reasons, accept its parameters in either order, explode() cannot. You must ensure that the
delimiterargument comes before thestringargument.
Return Values
Returns an array of strings
created by splitting the string parameter on
boundaries formed by the delimiter.
If delimiter is an empty string (""),
explode() will return FALSE.
If delimiter contains a value that is not
contained in string and a negative
limit is used, then an empty array will be
returned, otherwise an array containing
string will be returned.
Changelog
| Version | Description |
|---|---|
| 5.1.0 |
Support for negative limits was added
|
| 4.0.1 |
The limit parameter was added
|
Examples
Example #1 explode() examples
<?php
// Example 1
$pizza = "piece1 piece2 piece3 piece4 piece5 piece6";
$pieces = explode(" ", $pizza);
echo $pieces[0]; // piece1
echo $pieces[1]; // piece2
// Example 2
$data = "foo:*:1023:1000::/home/foo:/bin/sh";
list($user, $pass, $uid, $gid, $gecos, $home, $shell) = explode(":", $data);
echo $user; // foo
echo $pass; // *
?>
Example #2 explode() return examples
<?php
/*
A string that doesn't contain the delimiter will simply
return a one-length array of the original string.
*/
$input1 = "hello";
$input2 = "hello,there";
var_dump( explode( ',', $input1 ) );
var_dump( explode( ',', $input2 ) );
?>
The above example will output:
array(1)
(
[0] => string(5) "hello"
)
array(2)
(
[0] => string(5) "hello"
[1] => string(5) "there"
)
Example #3 limit parameter examples
<?php
$str = 'one|two|three|four';
// positive limit
print_r(explode('|', $str, 2));
// negative limit (since PHP 5.1)
print_r(explode('|', $str, -1));
?>
The above example will output:
Array
(
[0] => one
[1] => two|three|four
)
Array
(
[0] => one
[1] => two
[2] => three
)
Notes
Note: This function is binary-safe.
See Also
- preg_split() - Split string by a regular expression
- str_split() - Convert a string to an array
- mb_split() - Split multibyte string using regular expression
- str_word_count() - Return information about words used in a string
- strtok() - Tokenize string
- implode() - Join array elements with a string
- addcslashes
- addslashes
- bin2hex
- chop
- chr
- chunk_split
- convert_cyr_string
- convert_uudecode
- convert_uuencode
- count_chars
- crc32
- crypt
- echo
- explode
- fprintf
- get_html_translation_table
- hebrev
- hebrevc
- hex2bin
- html_entity_decode
- htmlentities
- htmlspecialchars_decode
- htmlspecialchars
- implode
- join
- lcfirst
- levenshtein
- localeconv
- ltrim
- md5_file
- md5
- metaphone
- money_format
- nl_langinfo
- nl2br
- number_format
- ord
- parse_str
- printf
- quoted_printable_decode
- quoted_printable_encode
- quotemeta
- rtrim
- setlocale
- sha1_file
- sha1
- similar_text
- soundex
- sprintf
- sscanf
- str_getcsv
- str_ireplace
- str_pad
- str_repeat
- str_replace
- str_rot13
- str_shuffle
- str_split
- str_word_count
- strcasecmp
- strchr
- strcmp
- strcoll
- strcspn
- strip_tags
- stripcslashes
- stripos
- stripslashes
- stristr
- strlen
- strnatcasecmp
- strnatcmp
- strncasecmp
- strncmp
- strpbrk
- strpos
- strrchr
- strrev
- strripos
- strrpos
- strspn
- strstr
- strtok
- strtolower
- strtoupper
- strtr
- substr_compare
- substr_count
- substr_replace
- substr
- trim
- ucfirst
- ucwords
- vfprintf
- vprintf
- vsprintf
- wordwrap
Коментарии
Be careful, while most non-alphanumeric data types as input strings return an array with an empty string when used with a valid separator, true returns an array with the string "1"!
var_dump(explode(',', null)); //array(1) { [0]=> string(0) "" }
var_dump(explode(',', false)); //array(1) { [0]=> string(0) "" }
var_dump(explode(',', true)); //array(1) { [0]=> string(1) "1" }
Note that an empty input string will still result in one element in the output array. This is something to remember when you are processing unknown input.
For example, maybe you are splitting part of a URI by forward slashes (like "articles/42/show" => ["articles", "42", "show"]). And maybe you expect that an empty URI will result in an empty array ("" => []). Instead, it will contain one element, with an empty string:
<?php
$uri = '';
$parts = explode('/', $uri);
var_dump($parts);
?>
Will output:
array(1) {
[0]=>
string(0) ""
}
And not:
array(0) {
}
If you want to directly take a specific value without having to store it in another variable, you can implement the following:
$status = 'Missing-1';
echo $status_only = explode('-', $status)[0];
// Missing
If your data is smaller than the expected count with the list expansion:
<?php
$data = "foo:*:1023:1000::/home/foo:/bin/sh";
list($user, $pass, $uid, $gid, $gecos, $home, $shell,$nu) = explode(":", $data);
?>
The result is a warning not an error:
PHP Warning: Undefined array key 7 in ...
The solution is to pad the array to the expected length:
<?php
$data = "foo:*:1023:1000::/home/foo:/bin/sh";
list($user, $pass, $uid, $gid, $gecos, $home, $shell,$nu) = array_pad( explode(":", $data), 8, "");
// where 8 is the count of the list arguments
?>