| Re: Fast/Easy way to extract a column from multi-dimensional array? [message #176834 is a reply to message #176833] |
Fri, 27 January 2012 21:42   |
Thomas 'PointedEars'
Messages: 701
Registered: October 2010
Karma:
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Senior Member |
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Thomas Mlynarczyk wrote:
> John Drako schrieb:
>> I'm looking for a way to get all the values from the column of a two
>> dimensional array.
>
>> RecordID, name, last name, title
>> RecordID, name, last name, title
>> RecordID, name, last name, title
>> RecordID, name, last name, title
>> RecordID, name, last name, title
>> RecordID, name, last name, title
>> etc...
>>
>> I need to get all the 'RecordID' from the results to reuse in other
>> queries.
>
> If it's the first column you're interested in:
>
> array_map( 'current', $array )
array_map() it is, but one should not rely on that the array cursor is at
the first element. Since the OP is passing MYSQLI_ASSOC, they should use
$recordIds = array_map(
create_function('$e', 'return $e["RecordID"]'),
$arr
);
for one-time use or
public static function getRecordId($result)
{
return $result['RecordID'];
}
public function getResults()
{
$arr = …;
$recordIds = array_map(array('self', 'getRecordId'), $arr);
}
in a class. Adjust visibility to the necessary minimum.
However, it is better to map the result of a database query to model objects
(cf. MVC pattern):
public function getResults()
{
$arr = …;
foreach ($arr as $row)
{
$results[] = new Result($row);
}
return $results;
}
The (example) `Result' constructor would then cause the elements of the
array to be mapped, according to their key, to properties of `Result'
instances, allowing for implicit range checking and type conversion through
setters (preferably the __set() magic method calling them on access of non-
public properties from public context).
PointedEars
--
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