PHP: 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.

Parameters

varname: A variable.

Return Values

No value is returned.

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 = 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>

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.

Note: list() only works on numerical arrays and assumes the numerical indices start at 0.

list

Description

Parameters

Return Values

Examples

Notes

See Also