Compact does not work with references, but there is a short way to resolve this:
<?php
//$foo=array();
foreach( array('apple','banana') as $v) $foo[$v] = &$v;
?>
compact
(PHP 4, PHP 5)
compact — Laver et array som indeholder variabler og deres værdier
Beskrivelse
compact() tager et variabel antal paramenter, og hver parameter kan enten være en streg som indeholder navnet på en variable eller et array med variablenavne. Arrayet kan indeholde andre arrays af variabelnavne; compact() behandler dem rekursivt.
Ved hver enkel, ser compact() efter en variable med det angivet navn og tilføjer det til arrayet med variablenavnet som nøgle med værdien af variable. Sagt kort, så gør den det modsatte af extract(). Den returnerer et array med alle variabler tilføjet i sig.
Alle strenge som ikke er sat, vil blive sprunget over.
Note: Bemærk Fordi variable variabler ikke kan bruges til at fremstille Superglobals arrays, Superglobal arrays skal derfor ikke køres igennem compact().
Example#1 compact() eksempel
<?php
$city = "San Francisco";
$state = "CA";
$event = "SIGGRAPH";
$location_vars = array("city", "state");
$result = compact("event", "nothing_here", $location_vars);
?>
Efter dette vil $result indeholde:
Array ( [event] => SIGGRAPH [city] => San Francisco [state] => CA )
Se også extract().
compact
06-Apr-2009 10:41
31-Jan-2008 05:46
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/>
24-May-2007 01:10
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
)
17-Nov-2005 07:38
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...
13-Jun-2005 03:43
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);
}
?>
22-Nov-2004 08:26
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
