implode

(PHP 4, PHP 5, PHP 7, PHP 8)

implodeUne elementos de un array en un string

Descripción

implode ( string $glue , array $pieces ) : string
implode ( array $pieces ) : string

Une elementos de un array en un string con glue (pegamento).

Nota:

Por razones históricas implode() puede aceptar parámetros en cualquier orden. Para mantener una consistencia respecto a explode(), sin embargo, es obsoleto no utilizar el orden documentado de los argumentos.

Parámetros

glue

Por defecto es un string vacío.

pieces

El array de strings a ser usados por implode.

Valores devueltos

Devuelve un string que contiene la representación de todos los elementos del array en el mismo orden, con el string 'glue' entre cada elemento.

Historial de cambios

Versión Descripción
7.4.0 Pasar el parámetro glue después de el parámetro pieces (es decir, sin utilizar el orden documentado de los parámetros) es obsoleto.

Ejemplos

Ejemplo #1 Ejemplo de implode()

<?php

$array 
= array('apellido''email''teléfono');
$separado_por_comas implode(","$array);

echo 
$separado_por_comas// apellido,email,teléfono

// Devuelve un string vacío si se usa un array vacío:
var_dump(implode('hola', array())); // string(0) ""

?>

Notas

Nota: Esta función es segura binariamente.

Ver también

add a note add a note

User Contributed Notes 14 notes

up
325
houston_roadrunner at yahoo dot com
12 years ago
it should be noted that an array with one or no elements works fine. for example:

<?php
    $a1
= array("1","2","3");
   
$a2 = array("a");
   
$a3 = array();
   
    echo
"a1 is: '".implode("','",$a1)."'<br>";
    echo
"a2 is: '".implode("','",$a2)."'<br>";
    echo
"a3 is: '".implode("','",$a3)."'<br>";
?>

will produce:
===========
a1 is: '1','2','3'
a2 is: 'a'
a3 is: ''
up
53
ASchmidt at Anamera dot net
2 years ago
It's not obvious from the samples, if/how associative arrays are handled. The "implode" function acts on the array "values", disregarding any keys:

<?php
declare(strict_types=1);

$a = array( 'one','two','three' );
$b = array( '1st' => 'four', 'five', '3rd' => 'six' );

echo
implode( ',', $a ),'/', implode( ',', $b );
?>

outputs:
one,two,three/four,five,six
up
103
omar dot ajoue at kekanto dot com
8 years ago
Can also be used for building tags or complex lists, like the following:

<?php

$elements
= array('a', 'b', 'c');

echo
"<ul><li>" . implode("</li><li>", $elements) . "</li></ul>";

?>

This is just an example, you can create a lot more just finding the right glue! ;)
up
20
Felix Rauch
4 years ago
It might be worthwhile noting that the array supplied to implode() can contain objects, provided the objects implement the __toString() method.

Example:
<?php

class Foo
{
    protected
$title;

    public function
__construct($title)
    {
       
$this->title = $title;
    }

    public function
__toString()
    {
        return
$this->title;
    }
}

$array = [
    new
Foo('foo'),
    new
Foo('bar'),
    new
Foo('qux')
];

echo
implode('; ', $array);
?>

will output:

foo; bar; qux
up
38
alexey dot klimko at gmail dot com
9 years ago
If you want to implode an array of booleans, you will get a strange result:
<?php
var_dump
(implode('',array(true, true, false, false, true)));
?>

Output:
string(3) "111"

TRUE became "1", FALSE became nothing.
up
54
php.net {at} nr78 {dot} net
16 years ago
Also quite handy in INSERT statements:

<?php

  
// array containing data
  
$array = array(
     
"name" => "John",
     
"surname" => "Doe",
     
"email" => "j.doe@intelligence.gov"
  
);

  
// build query...
  
$sql  = "INSERT INTO table";

  
// implode keys of $array...
  
$sql .= " (`".implode("`, `", array_keys($array))."`)";

  
// implode values of $array...
  
$sql .= " VALUES ('".implode("', '", $array)."') ";

  
// execute query...
  
$result = mysql_query($sql) or die(mysql_error());

?>
up
22
Anonymous
8 years ago
It may be worth noting that if you accidentally call implode on a string rather than an array, you do NOT get your string back, you get NULL:
<?php
var_dump
(implode(':', 'xxxxx'));
?>
returns
NULL

This threw me for a little while.
up
17
masterandujar
8 years ago
Even handier if you use the following:

<?php
$id_nums
= array(1,6,12,18,24);

$id_nums = implode(", ", $id_nums);
               
$sqlquery = "Select name,email,phone from usertable where user_id IN ($id_nums)";

// $sqlquery becomes "Select name,email,phone from usertable where user_id IN (1,6,12,18,24)"
?>

Be sure to escape/sanitize/use prepared statements if you get the ids from users.
up
2
Honk der Hase
11 months ago
If you want to implode an array as key-value pairs, this method comes in handy.
The third parameter is the symbol to be used between key and value.

<?php
function mapped_implode($glue, $array, $symbol = '=') {
    return
implode($glue, array_map(
            function(
$k, $v) use($symbol) {
                return
$k . $symbol . $v;
            },
           
array_keys($array),
           
array_values($array)
            )
        );
}

$arr = [
   
'x'=> 5,
   
'y'=> 7,
   
'z'=> 99,
   
'hello' => 'World',
   
7 => 'Foo',
];

echo
mapped_implode(', ', $arr, ' is ');

// output: x is 5, y is 7, z is 99, hello is World, 7 is Foo

?>
up
5
Anonymous
5 years ago
null values are imploded too. You can use array_filter() to sort out null values.

<?php
$ar
= array("hello", null, "world");
print(
implode(',', $ar)); // hello,,world
print(implode(',', array_filter($ar, function($v){ return $v !== null; }))); // hello,world
?>
up
0
biziclop
2 days ago
Sometimes it's necessary to add a string not just between the items, but before or after too, and proper handling of zero items is also needed.
In this case, simply prepending/appending the separator next to implode() is not enough, so I made this little helper function.

<?php

function wrap_implode( $array, $before = '', $after = '', $separator = '' ){
  if( !
$array )  return '';
  return
$before . implode("{$after}{$separator}{$before}", $array ) . $after;
}

echo
wrap_implode(['path','to','file.php'], '/');
// "/path/to/file.php"

$pattern = '#'. wrap_implode([4,2,2], '\d{', '}', '[-.]') .'#';
echo
$pattern, "\n"// #\d{4}[-.]\d{2}[-.]\d{2}#
echo preg_replace( $pattern, '[REDACTED]', 'The UFO appeared between 2012-12-24 and 2013.01.06 every night.');
// 'The UFO appeared between [REDACTED] and [REDACTED] every night.

echo wrap_implode(['line','by','line'], '<b>', '</b>', '<br>  ');
// <b>line</b><br>  <b>by</b><br>  <b>line</b>

echo wrap_implode( ['<a href="">Menu Item 1</a>', '<a href="">Menu Item 2</a>',],
 
"<li>", "</li>\n",
 
"<li> | </li>\n",
);
/*
<li><a href="">Link1</a></li>
<li> | </li>
<li><a href="">Link2</a></li>
*/

?>
up
-2
Rafael Pereira
1 year ago
If you want to use a key inside array:

Example:
$arr=array(
array("id" => 1,"name" => "Test1"),
array("id" => 2,"name" => "Test2"),
);

echo implode_key(",",$arr, "name");
OUTPUT: Test1, Test2

function implode_key($glue, $arr, $key){
    $arr2=array();
    foreach($arr as $f){
        if(!isset($f[$key])) continue;
        $arr2[]=$f[$key];
    }
    return implode($glue, $arr2);
}
up
-26
admin at lanlink dot net dot au
3 years ago
It is possible for an array to have numeric values, as well as string values. Implode will convert all numeric array elements to strings.

<?php
$test
=implode(["one",2,3,"four",5.67]);
echo
$test;
//outputs: "one23four5.67"
?>
up
-8
info at ensostudio dot ru
7 months ago
<?php
* Join pieces with a string recursively.
*
* @
param mixed $glue String between pairs(glue) or an array pair's glue and key/value glue or $pieces.
* @param iterable $pieces Pieces to implode (optional).
* @return string Joined string
*/
function double_implode($glue, iterable $pieces = null): string
{
    $glue2 = null;
    if ($pieces === null) {
        $pieces = $glue;
        $glue = '';
    } elseif (is_array($glue)) {
        list($glue, $glue2) = $glue;
    }
   
    $result = [];
    foreach ($pieces as $key => $value) {
        $result[] = $glue2 === null ? $value : $key . $glue2 . $value;
    }
    return implode($glue, $result);
}
?>
Examples:
<?php
$array = ['
a' => 1, 'b' => 2];
$str =  implode($array);
$str =  implode('
, ', $array);
$str =  implode(['" ', '="'], $array);

$iterator = new ArrayIterator($array);
$str =  implode($iterator);
$str =  implode('
, ', $iterator);
$str =  implode(['" ', '="'], $iterator);
?>
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