(PHP 4, PHP 5, PHP 7, PHP 8)
explode — Split a string by a string
Returns an array of strings, each of which is a substring of
string
formed by splitting it on
boundaries formed by the string separator
.
separator
The boundary string.
string
The input string.
limit
If limit
is set and positive, the returned array will contain
a maximum of limit
elements with the last
element containing the rest of string
.
If the limit
parameter is negative, all components
except the last -limit
are returned.
If the limit
parameter is zero, then this is treated as 1.
Note:
Prior to PHP 8.0, implode() accepted its parameters in either order. explode() has never supported this: you must ensure that the
separator
argument comes before thestring
argument.
Returns an array of string s
created by splitting the string
parameter on
boundaries formed by the separator
.
If separator
is an empty string (""),
explode() throws a ValueError .
If separator
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. If separator
values appear at the start or end of string
, said values
will be added as an empty array value either in the first or last
position of the returned array respectively.
Version | Description |
---|---|
8.0.0 |
explode() will now throw ValueError
when separator parameter is given an empty string
("" ).
Previously, explode() returned false instead.
|
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";
$input3 = ',';
var_dump( explode( ',', $input1 ) );
var_dump( explode( ',', $input2 ) );
var_dump( explode( ',', $input3 ) );
?>
The above example will output:
array(1) ( [0] => string(5) "hello" ) array(2) ( [0] => string(5) "hello" [1] => string(5) "there" ) array(2) ( [0] => string(0) "" [1] => string(0) "" )
Example #3 limit
parameter examples
<?php
$str = 'one|two|three|four';
// positive limit
print_r(explode('|', $str, 2));
// negative limit
print_r(explode('|', $str, -1));
?>
The above example will output:
Array ( [0] => one [1] => two|three|four ) Array ( [0] => one [1] => two [2] => three )
Note: This function is binary-safe.
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 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
?>
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" }
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