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 — Divide uma string em strings
Valor Retornado
Retorna uma matriz de strings, cada uma como substring de string formada pela divisão dela a partir do delimiter .
Parâmetros
- delimiter
-
O delimitador.
- string
-
A string de entrada.
- limit
-
Se limit é definido, o array retornado irá conter o máximo de elementos igual a limit com o último elemento contendo o resto da string .
Se o parâmetro limit é negativo, todos componentes exceto o último -limit são retornados.
Ainda que implode() pode por razões históricas aceitar seus parâmetros em uma das duas ordens, explode() não pode. Você deve assegurar que o argumento delimiter vem antes do argumento string .
Valor Retornado
Se delimiter é uma string vazia (""), explode() irá retornar FALSE. Se delimiter contém um valor que não contém em string , então explode() irá retornar um array contendo string .
Histórico
| Versão | Descrição |
|---|---|
| 5.1.0 | Suporte a limit negativo foi adicionado |
| 4.0.1 | O parâmetro limit foi adicionado |
Exemplos
Exemplo #1 explode() exemplos
<?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; // *
?>
Exemplo #2 Exemplos de parâmetro limit
<?php
$str = 'one|two|three|four';
// positive limit
print_r(explode('|', $str, 2));
// negative limit (since PHP 5.1)
print_r(explode('|', $str, -1));
?>
O exemplo acima irá imprimir:
Array
(
[0] => one
[1] => two|three|four
)
Array
(
[0] => one
[1] => two
[2] => three
)
Notas
Nota: Esta função é compatível com dados binários
Veja Também
- preg_split() - Divide a string por uma expressão regular
- str_split() - Converte uma string para um array
- str_word_count() - Retorna informação sobre as palavras usadas em uma string
- strtok() - Tokeniza uma string
- implode() - Junta elementos de uma matriz em uma string
explode
15-Jun-2009 10:50
21-Apr-2009 11:50
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(' ', $foo));
?>
Array
(
[0] => uno
[1] => dos
[2] =>
[3] => tres
)
Needless to say this is definitely not intuitive and must be handled carefully.
19-Apr-2009 06:29
Here's a simple script which uses explode() to check to see if an IP address is in an array (can be used as a ban-check, without needing to resort to database storage and queries).
<?php
function denied($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($_SERVER['REMOTE_ADDR'])) {
header('Location: denied.php');
}
?>
31-Mar-2009 09:03
<?php
function my_explode($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])), $out[1]);
}
?>
This function can assume `limit' parameter less than 0, for example:
<?php
print_r(my_explode('.', 'file.some.ext.jpg', -2));
?>
prints
Array
(
[0] => file.some.ext
[1] => jpg
)
23-Feb-2009 07:40
<?php
function explode_escaped($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
)
05-Dec-2008 02:02
<?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;
}
?>
16-Nov-2008 10:38
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 :)
29-Aug-2008 04:24
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.)
15-Oct-2007 06:26
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. :)
10-Dec-2006 12:49
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));
?>
01-Dec-2004 09:50
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.
16-Nov-2003 01:01
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");
