Array Functions
PHP Manual

list

Assign variables as if they were an array

Description

array list ( mixed $var1 [, mixed $... ] )

Like array, this is not really a function, but a language construct. list is used to assign a list of variables in one operation.

Parameters

var1

A variable.

Return Values

Returns the assigned array.

Examples

Example #1 list examples

<?php

$info = array('coffee', 'brown', 'caffeine');

// Listing all the variables
list($drink, $color, $power) = $info;
echo "$drink is $color and $power makes it special.\n";

// Listing some of them
list($drink, , $power) = $info;
echo "$drink has $power.\n";

// Or let's skip to only the third one
list( , , $power) = $info;
echo "I need $power!\n";

// list() doesn't work with strings
list($bar) = "abcde";
var_dump($bar); // NULL
?>

Example #2 An example use of list

<table>
 <tr>
  <th>Employee name</th>
  <th>Salary</th>
 </tr>

<?php
$result = $pdo->query("SELECT id, name, salary FROM employees");
while (list($id, $name, $salary) = $result->fetch(PDO::FETCH_NUM)) {
    echo " <tr>\n" .
          "  <td><a href=\"info.php?id=$id\">$name</a></td>\n" .
          "  <td>$salary</td>\n" .
          " </tr>\n";
}

?>

</table>

Example #3 Using nested list

<?php

list($a, list($b, $c)) = array(1, array(2, 3));

var_dump($a, $b, $c);

?> 
int(1)
int(2)
int(3)

Example #4 Using list with array indices

<?php

$info = array('coffee', 'brown', 'caffeine');

list($a[0], $a[1], $a[2]) = $info;

var_dump($a);

?>

Gives the following output (note the order of the elements compared in which order they were written in the list syntax): 

array(3) {
  [2]=>
  string(8) "caffeine"
  [1]=>
  string(5) "brown"
  [0]=>
  string(6) "coffee"
}

Notes

Warning

list assigns the values starting with the right-most parameter. If you are using plain variables, you don't have to worry about this. But if you are using arrays with indices you usually expect the order of the indices in the array the same you wrote in the list from left to right; which it isn't. It's assigned in the reverse order.

Warning

Modification of the array during list execution (e.g. using list($a, $b) = $b) results in undefined behavior.

Note:

list only works on numerical arrays and assumes the numerical indices start at 0.

See Also

  • each
  • array
  • extract