asort
You can check whether a variable is defined by using array_key_exists()!
First, you may ask that no reserved array (would be called $LOCALS) is predefined in function scope (contrast to reserved array $GLOBALS in global scope. To solve it, you can use compact().
Then, you may ask that why property_exists() cannot be used. This is because no reserved function is predefined to create OBJECT containing variables and their values, and no reserved function is predefined to import variables into the current symbol table from an OBJECT. In addition, property_exists() breaks the naming convention of reserved function.
Finally, I show how to check whether a variable is defined by using array_key_exists():
<?php
function too(){
$roo = array_key_exists('foo', compact('foo'));
echo ($roo?'1':'0').'<br/>';
$foo = null;
$roo = array_key_exists('foo', compact('foo'));
echo ($roo?'1':'0').'<br/>';
}
too();
?>
The output will be:
0<br/>
1<br/>
compact
(PHP 4, PHP 5)
compact — Crée un tableau à partir de variables et de leur valeur
Description
Crée un tableau à partir de variables et de leur valeur.
Pour chacun des arguments varname , ... , compact() recherche une variable avec un même nom dans la table courante des symboles, et l'ajoute dans le tableau, de manière à avoir la relation nom => 'valeur de variable'. En bref, c'est le contraire de la fonction extract().
Toute chaîne non reconnue dans la table des symboles sera tout simplement ignorée.
Liste de paramètres
- varname
-
compact() accepte différents paramètres varname . Les paramètres peuvent être des variables contenant des chaînes, ou un tableau de chaînes, qui peut contenir d'autres tableaux de noms de variables, que compact() traitera récursivement.
Valeurs de retour
Retourne le tableau de sortie contenant toutes les variables ajoutées.
Exemples
Exemple #1 Exemple avec compact()
<?php
$city = "San Francisco";
$state = "CA";
$event = "SIGGRAPH";
$location_vars = array("city", "state");
$result = compact("event", "nothing_here", $location_vars);
print_r($result);
?>
L'exemple ci-dessus va afficher :
Array ( [event] => SIGGRAPH [city] => San Francisco [state] => CA )
Notes
Note: Gotcha Parce que les variables variables ne doivent pas être utilisées avec les tableaux Superglobaux dans des fonctions, les tableaux Superglobaux ne doivent pas être passés dans la fonction compact().
add a note
User Contributed Notescompact
packard_bell_nec at hotmail dot com
31-Jan-2008 09:46
31-Jan-2008 09:46
M Spreij
24-May-2007 06:10
24-May-2007 06:10
Can also handy for debugging, to quickly show a bunch of variables and their values:
<?php
print_r(compact(explode(' ', 'count acw cols coldepth')));
?>
gives
Array
(
[count] => 70
[acw] => 9
[cols] => 7
[coldepth] => 10
)
mijllirg at wearethedotin dot com
17-Nov-2005 11:38
17-Nov-2005 11:38
You might could think of it as ${$var}. So, if you variable is not accessible with the ${$var} it will not working with this function. Examples being inside of function or class where you variable is not present.
<?php
$foo = 'bar';
function blah()
{
// this will no work since the $foo is not in scope
$somthin = compact('foo'); // you get empty array
}
?>
PS: Sorry for my poor english...
hericklr at gmail dot com
13-Jun-2005 08:43
13-Jun-2005 08:43
The compact function doesn't work inside the classes or functions.
I think its escope is local...
Above it is a code to help about it.
Comments & Suggestions are welcome.
PS: Sorry for my poor english...
<?php
function x_compact()
{ if(func_num_args()==0)
{ return false; }
$m=array();
function attach($val)
{ global $m;
if((!is_numeric($val)) && array_key_exists($val,$GLOBALS))
{ $m[$val]=$GLOBALS[$val];}
}
function sub($par)
{ global $m;
if(is_array($par))
{ foreach($par as $cel)
{ if(is_array($cel))
{ sub($cel); }
else
{ attach($cel); }
}
}
else
{ attach($par); }
return $m;
}
for($i=0;$i<func_num_args();$i++)
{ $arg=func_get_arg($i);
sub($arg);
}
return sub($arg);
}
?>
pillepop2003 at yahoo dot de
22-Nov-2004 12:26
22-Nov-2004 12:26
Use the following piece of code if you want to insert a value into an array at a path that is extracted from a string.
Example:
You have a syntax like 'a|b|c|d' which represents the array structure, and you want to insert a value X into the array at the position $array['a']['b']['c']['d'] = X.
<?
function array_path_insert(&$array, $path, $value)
{
$path_el = split('\|', $path);
$arr_ref =& $array;
for($i = 0; $i < sizeof($path_el); $i++)
{
$arr_ref =& $arr_ref[$path_el[$i]];
}
$arr_ref = $value;
}
$array['a']['b']['f'] = 4;
$path = 'a|b|d|e';
$value = 'hallo';
array_path_insert($array, $path, $value);
/* var_dump($array) returns:
array(1) {
["a"]=>
&array(1) {
["b"]=>
&array(2) {
["f"]=>
int(4)
["d"]=>
&array(1) {
["e"]=>
string(5) "hallo"
}
}
}
*/
?>
Rock on
Philipp