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implode

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

implode配列要素を文字列により連結する

説明

implode(string $separator, array $array): string

代替のシグネチャ(名前付き引数をサポートしていません):

implode(array $array): string

古いシグネチャ(PHP 7.4.0 で非推奨となり、PHP 8.0.0 以降は削除されています):

implode(array $array, string $separator): string

配列の要素を separator 文字列で連結します。

パラメータ

separator

オプションです。 デフォルトは空文字列です。

array

連結したい文字列の配列。

戻り値

すべての配列要素の順序を変えずに、各要素間に separator 文字列をはさんで 1 つの文字列にして返します。

変更履歴

バージョン 説明
8.0.0 array の後に separator を渡すことは、サポートされなくなりました。
7.4.0 array の後に separator を渡すこと (つまり、古いシグネチャを使うこと) は、推奨されなくなりました。

例1 implode() の例

<?php

$array
= ['lastname', 'email', 'phone'];
var_dump(implode(",", $array)); // string(20) "lastname,email,phone"

// 空の配列を使うと空文字列となります
var_dump(implode('hello', [])); // string(0) ""

// separator はオプションです。
var_dump(implode(['a', 'b', 'c'])); // string(3) "abc"

?>

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

add a note

User Contributed Notes 9 notes

up
364
houston_roadrunner at yahoo dot com
15 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
98
ASchmidt at Anamera dot net
5 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
104
omar dot ajoue at kekanto dot com
11 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
27
Felix Rauch
8 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
47
alexey dot klimko at gmail dot com
13 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
9
Honk der Hase
4 years 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
20
Anonymous
11 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
13
masterandujar
12 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
7
Anonymous
9 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
?>