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
)
(PHP 4, PHP 5, PHP 7)
compact — 변수와 그 값을 가지는 배열 생성
변수와 그 값을 가지는 배열을 생성합니다.
이들 각각에 대해, compact() 는 현재 심볼 테이블에서 그 이름을 갖는 변수를 찾고, 그 변수명이 키가 되고 변수의 내용은 그 키에 대한 값이 될수 있도록 출력 배열에 추가한다. 짧게 말해서, 이 함수는 extract()과 반대이다.
선언되지 않은 모든 문자열은 단순히 무시합니다.
varname
compact()는 가변 인수를 가집니다. 각 인수는 변수명을 가지는 문자열이거나, 변수명의 배열일 수 있습니다. 배열은 그 안에 변수명을 가지는 다른 배열을 포함할 수 있습니다; compact()는 재귀적으로 다룹니다.
모든 변수를 추가한 결과 배열을 반환합니다.
Example #1 compact() 예제
<?php
$city = "San Francisco";
$state = "CA";
$event = "SIGGRAPH";
$location_vars = array("city", "state");
$result = compact("event", "nothing_here", $location_vars);
?>
위 예제의 출력:
Array ( [event] => SIGGRAPH [city] => San Francisco [state] => CA )
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
)
Consider these two examples. The first as used in the manual, and the second a slight variation of it.
Example #1
<?php
$city = "San Francisco";
$state = "CA";
$event = "SIGGRAPH";
$location_vars = array("city", "state");
$result = compact("event", $location_vars);
print_r($result);
?>
Example #1 above will output:
Array
(
[event] => SIGGRAPH
[city] => San Francisco
[state] => CA
)
Example #2
<?php
$city = "San Francisco";
$state = "CA";
$event = "SIGGRAPH";
$location_vars = array("city", "state");
$result = compact("event", "location_vars");
print_r($result);
?>
Example #2 above will output:
Array
(
[event] => SIGGRAPH
[location_vars] => Array
(
[0] => city
[1] => state
)
)
In the first example, the value of the variable $location_values (which is an array containing city, and state) is passed to compact().
In the second example, the name of the variable $location_vars (i.e without the '$' sign) is passed to compact() as a string. I hope this further clarifies the points made in the manual?
So compact('var1', 'var2') is the same as saying array('var1' => $var1, 'var2' => $var2) as long as $var1 and $var2 are set.
The description says that compact is the opposite of extract() but it is important to understand that it does not completely reverse extract(). In particluar compact() does not unset() the argument variables given to it (and that extract() may have created). If you want the individual variables to be unset after they are combined into an array then you have to do that yourself.
If you must utilise this knowing that a variable may be unset, then you need to use an alternative method.
So instead of the following:
<?php
$var1 = "lorem";
$var2 = "ipsum";
$result = compact('var1', 'var2', 'unsetvar');
?>
Consider the following:
<?php
$var1 = "lorem";
$var2 = "ipsum";
$result = [];
foreach( ['var1', 'var2', 'unsetvar'] as $attr ) {
if ( isset( $$attr ) ) {
$result[ $attr ] = $$attr;
}
}
?>