PHP array mapping

Question

Is there a cleaner way than foreach to get an array of all label values?

 $methods[0]['label'] = 'test'; $methods[0]['nr'] = 99; $methods[1]['label'] = 'whatever'; $methods[1]['nr'] = 10; foreach($methods as $method) { $methodsLabel[] = $method['label']; } 

Answer 1

No, there is no faster way than your implemented code. All other methods will be slower due to the overhead of calling the function. For a small array, the difference will be trivial, but for a large (100 members or so, depending on implementation) the difference can be huge ...

You could array_map it, but I would stick with the raw PHP that you posted above ... It is easier to maintain and IMHO more readable ...

In the end, tell me which, at first glance, it says that it does more:

 $results = array(); foreach ($array as $value) { $results[] = $value['title']; } 

vs

 $results = array_map(function($element) { return $element['title']; }, $array ); 

Or:

 $callback = function($element) { return $element['title']; } $results = array_map($callback, $array); 

Personally, the first one makes it the best for me. This immediately becomes apparent, not knowing anything that he does. Others require knowledge of the semantics of array_map to understand. A couple that with the fact that array_map slower, and this is a double win for foreach .

The code should only be as elegant as necessary. It should be readable, first of all ...

Answer 2

Of course use array_map :

 function getLabelFromMethod($method) { return $method['label']; } $labels = array_map('getLabelFromMethod', $methods); 

If you are using PHP 5.3+, you can also use the lambda function:

 $labels = array_map(function($m) { return $m['label']; }, $methods); 

Answer 3

 array_map('array_shift', $methods); 

Here it is assumed that the label will be the first element of each array.

Answer 4

In PHP 5.3+, you can use an anonymous function paired with array_map.

 $methodsLabel = array_map(function($item) { return $item['label']; }, $methods); 

Answer 5

Starting with PHP 5. 5+, this is exactly what array_column does:

 $methodsLabel = array_column($methods, 'label'); 

http://php.net/manual/function.array-column.php

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3v4l example: https://3v4l.org/ZabAb

Answer 6

If the label is the first element in the array, then "current" with array_map will work fine.

 array_map('current', $methods);