How can I create a subsection of an existing array using PHP?
I know this is probably a very simple question but I have looked around and most answers relate to array intersections which is not what I am looking for.
Example:
I have an array ($rows). When running print_r($rows)
I get:
Array (
[0] => Array (
[id] => 184
[0] => 184
[name] => Advantage Membership
[1] => Advantage Membership
[flag] => 4
[2] => 4
)
[1] => Array (
[id] =>开发者_如何转开发; 238
[0] => 238
[programname] => Package 2
[1] => Package 2
[flag] => 5
[2] => 5
)
)
I want to essentially create a 'sub' array which contains all of the 'flag' fields in my $rows array so that I can THEN do a if(in_array()) statement with another value.
ideal result array would look like:
$array2 = array( '4', '5' )
Then I could run the following and be happy:
if (in_array(4, $array2)) ...
Any suggestions?
What's wrong with a custom function?
function in_sub_array($needle, $ary){
foreach ($ary as $a){
if (isset($a['flag']) && $a['flag'] == $needle) // could use ===, too.
return true;
}
return false;
}
if (in_sub_arry(4,$array2)) ...
Or, as others have suggested, array_map
is a good alternative.
function get_flags($ary){
return (isset($ary['flag']) ? $ary['flag'] : null);
}
if (in_array(4,array_map('get_flags',$array2))) ...
demos of both methods
function flagit($n)
{
return $n['flag'];
}
$flags = array_map("flagit", $array);
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