list
(PHP 3, PHP 4, PHP 5)
list --
Assign variables as if they were an array
Description
void
list ( mixed varname, 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.
Note:
list() only works on numerical arrays and assumes
the numerical indices start at 0.
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";
?>
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Example 2. An example use of list()
<table>
<tr>
<th>Employee name</th>
<th>Salary</th>
</tr>
<?php
$result = mysql_query("SELECT id, name, salary FROM employees", $conn);
while (list($id, $name, $salary) = mysql_fetch_row($result)) {
echo " <tr>\n" .
" <td><a href=\"info.php?id=$id\">$name</a></td>\n" .
" <td>$salary</td>\n" .
" </tr>\n";
}
?>
</table>
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| 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.
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Example 3. Using list() with array indices
<?php
$info = array('coffee', 'brown', 'caffeine');
list($a[0], $a[1], $a[2]) = $info;
var_dump($a);
?>
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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"
} |
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See also each(), array()
and extract().