echo
Just in case the comment about empty strings is not clear:
<?php
$a = array();
var_dump($a);
$s = implode("\n", $a);
var_dump($s);
$b = explode("\n", $s);
var_dump($b);
$b = preg_split('/\n/', $s,-1,PREG_SPLIT_NO_EMPTY);
var_dump($b);
?>
Results in:
array(0) {
}
string(0) ""
array(1) {
[0]=>
string(0) ""
}
array(0) {
}
i.e. exploding an empty string results in an array with one element. You can use preg_split to skip the empty item, but that may not be quite what you need should your array have empty elements intentionally.
explode
(PHP 4, PHP 5)
explode — 文字列を文字列により分割する
説明
array explode
( string $delimiter
, string $string
[, int $limit
] )
文字列の配列を返します。この配列の各要素は、 string を文字列 delimiter で区切った部分文字列となります。
パラメータ
- delimiter
-
区切り文字列。
- string
-
入力文字列。
- limit
-
limit に正の値が指定された場合、返される配列には 最大 limit の要素が含まれ、その最後の要素には string の残りの部分が全て含まれます。
もし limit パラメータが負の場合、 最後の -limit 個の要素を除く全ての構成要素が返されます。
limit パラメータがゼロの場合は、1 を指定したものとみなされます。
歴史的理由により、implode() はいずれのパラメータ順も受け入れることができますが、 explode() はそうできません。 string 引数の前に必ず delimiter 引数がくるように確認する必要があります。
返り値
空の文字列 ("") が delimiter として使用された場合、 explode() は FALSE を返します。delimiter に引数 string に含まれていない値が含まれおり、かつ limit に負の値が指定されている場合、 explode() は引数 string を含む配列を返します。
変更履歴
| バージョン | 説明 |
|---|---|
| 5.1.0 | limit に負の数を指定できるようになりました。 |
| 4.0.1 | limit パラメータが追加されました。 |
例
例1 explode() の例
<?php
// 例 1
$pizza = "piece1 piece2 piece3 piece4 piece5 piece6";
$pieces = explode(" ", $pizza);
echo $pieces[0]; // piece1
echo $pieces[1]; // piece2
// 例 2
$data = "foo:*:1023:1000::/home/foo:/bin/sh";
list($user, $pass, $uid, $gid, $gecos, $home, $shell) = explode(":", $data);
echo $user; // foo
echo $pass; // *
?>
例2 limit パラメータの例
<?php
$str = 'one|two|three|four';
// 正の値を持つ limit
print_r(explode('|', $str, 2));
// 負の値を持つ limit (PHP 5.1 以降)
print_r(explode('|', $str, -1));
?>
上の例の出力は以下となります。
Array
(
[0] => one
[1] => two|three|four
)
Array
(
[0] => one
[1] => two
[2] => three
)
注意
注意: この関数はバイナリデータに対応しています。
参考
- preg_split() - 正規表現で文字列を分割する
- str_split() - 文字列を配列に変換する
- str_word_count() - 文字列に使用されている単語についての情報を返す
- strtok() - 文字列をトークンに分割する
- implode() - 配列要素を文字列により連結する
add a note
User Contributed Notesexplode
marcus at synchromedia dot co dot uk
15-Jun-2009 01:50
15-Jun-2009 01:50
SR
21-Apr-2009 02:50
21-Apr-2009 02:50
Keep in mind that explode() can return empty elements if the delimiter is immediately repeated twice (or more), as shown by the following example:
<?php
$foo = 'uno dos tres'; // two spaces between "dos" and "tres"
print_r(explode(' ', $foo));
?>
Array
(
[0] => uno
[1] => dos
[2] =>
[3] => tres
)
Needless to say this is definitely not intuitive and must be handled carefully.
Michael
19-Apr-2009 09:29
19-Apr-2009 09:29
Here's a simple script which uses explode() to check to see if an IP address is in an array (can be used as a ban-check, without needing to resort to database storage and queries).
<?php
function denied($one) {
$denied = array(
0 => '^255.255.255.255',
1 => '^255.250',
2 => '^255.255.250'
);
for ($i = 0 ; $i < sizeof($denied) ; $i++) {
if (sizeof(explode($denied[$i], '^' . $one . '$')) == 2) {
return true;
}
}
return false;
}
if (denied($_SERVER['REMOTE_ADDR'])) {
header('Location: denied.php');
}
?>
Navi
31-Mar-2009 12:03
31-Mar-2009 12:03
<?php
function my_explode($delim, $str, $lim = 1)
{
if ($lim > -2) return explode($delim, $str, abs($lim));
$lim = -$lim;
$out = explode($delim, $str);
if ($lim >= count($out)) return $out;
$out = array_chunk($out, count($out) - $lim + 1);
return array_merge(array(implode($delim, $out[0])), $out[1]);
}
?>
This function can assume `limit' parameter less than 0, for example:
<?php
print_r(my_explode('.', 'file.some.ext.jpg', -2));
?>
prints
Array
(
[0] => file.some.ext
[1] => jpg
)
adrian at bilsoftware dot com
23-Feb-2009 10:40
23-Feb-2009 10:40
<?php
function explode_escaped($delimiter, $string){
$exploded = explode($delimiter, $string);
$fixed = array();
for($k = 0, $l = count($exploded); $k < $l; ++$k){
if($exploded[$k][strlen($exploded[$k]) - 1] == '\\') {
if($k + 1 >= $l) {
$fixed[] = trim($exploded[$k]);
break;
}
$exploded[$k][strlen($exploded[$k]) - 1] = $delimiter;
$exploded[$k] .= $exploded[$k + 1];
array_splice($exploded, $k + 1, 1);
--$l;
--$k;
} else $fixed[] = trim($exploded[$k]);
}
return $fixed;
}
?>
Here's a function which explodes string with delimiter, but if delimiter is "escaped" by backslash, function won't split in that point. Example:
<?php
$result = explode_escaped(',', 'string, piece, group\, item\, item2, next\,asd');
print_r($result);
?>
Will give:
Array
(
[0] => string
[1] => piece
[2] => group, item, item2
[3] => next,asd
)
Elad Elrom
05-Dec-2008 05:02
05-Dec-2008 05:02
<?php
// Remove words if more than max allowed character are insert or add a string in case less than min are displayed
// Example: LimitText("The red dog ran out of thefence",15,20,"<br>");
function LimitText($Text,$Min,$Max,$MinAddChar) {
if (strlen($Text) < $Min) {
$Limit = $Min-strlen($Text);
$Text .= $MinAddChar;
}
elseif (strlen($Text) >= $Max) {
$words = explode(" ", $Text);
$check=1;
while (strlen($Text) >= $Max) {
$c=count($words)-$check;
$Text=substr($Text,0,(strlen($words[$c])+1)*(-1));
$check++;
}
}
return $Text;
}
?>
Nobody
17-Nov-2008 01:38
17-Nov-2008 01:38
A really better and shorter way to get extension is via:
<?php $extension = end(explode('.', $filename)); ?>
this will print the last part after the last dot :)
shaun
29-Aug-2008 07:24
29-Aug-2008 07:24
For anyone trying to get an array of key => value pairs from a query string, use parse_str. (Better alternative than the explode_assoc function listed way down the page unless you need different separators.)
pinkgothic at gmail dot com
15-Oct-2007 09:26
15-Oct-2007 09:26
coroa at cosmo-genics dot com mentioned using preg_split() instead of explode() when you have multiple delimiters in your text and don't want your result array cluttered with empty elements. While that certainly works, it means you need to know your way around regular expressions... and, as it turns out, it is slower than its alternative. Specifically, you can cut execution time roughly in half if you use array_filter(explode(...)) instead.
Benchmarks (using 'too many spaces'):
Looped 100000 times:
preg_split: 1.61789011955 seconds
filter-explode: 0.916578054428 seconds
Looped 10000 times:
preg_split: 0.162719011307 seconds
filter-explode: 0.0918920040131 seconds
(The relation is, evidently, pretty linear.)
Note: Adding array_values() to the filter-explode combination, to avoid having those oft-feared 'holes' in your array, doesn't remove the benefit, either. (For scale - the '9' becomes a '11' in the benchmarks above.)
Also note: I haven't tested anything other than the example with spaces - since djogo_curl at yahoo's note seems to imply that explode() might get slow with longer delimiters, I expect this would be the case here, too.
I hope this helps someone. :)
seventoes at gmail dot com
10-Dec-2006 03:49
10-Dec-2006 03:49
Note that explode, split, and functions like it, can accept more than a single character for the delimiter.
<?php
$string = "Something--next--something else--next--one more";
print_r(explode('--next--',$string));
?>
djogo_curl at yahoo
01-Dec-2004 12:50
01-Dec-2004 12:50
Being a beginner in php but not so in Perl, I was used to split() instead of explode(). But as split() works with regexps it turned out to be much slower than explode(), when working with single characters.
coroa at cosmo-genics dot com
16-Nov-2003 04:01
16-Nov-2003 04:01
To split a string containing multiple seperators between elements rather use preg_split than explode:
preg_split ("/\s+/", "Here are to many spaces in between");
which gives you
array ("Here", "are", "to", "many", "spaces", "in", "between");