CODEWITHSUNDEEP
phparraysforeach
halorox
halorox

Reputation: 37

Quickly creating a reference arrays

I often run into this situation:

foreach ($someObjects as &$someObject)
{
  $someObjectsIndex[$someObject->id] = $someObject;
}

And this:

$thingsIActuallyWant = [];
foreach ($associativeList as &$associativeItem)
{
  $thingsIActuallyWant[] = $associativeItem['id'];
}

I was wondering if there is an existing method or something to write these things shorter, without writing the foreach loop.

Upvotes: 1

Views: 42

Answers (2)

gen_Eric
gen_Eric

Reputation: 227290

You can use array_map to return you an array of just the elements you want.

For the 2nd example:

$thingsIActuallyWant = array_map(function($a){
    return $a['id'];
}, $associativeList);

As for the 1st, I suggest using the foreach as you have, because any alternative is going to be an ugly mess of array_map and array_combine.

Upvotes: 2

Jimmy Sawczuk
Jimmy Sawczuk

Reputation: 13614

You might try writing a function yourself, something like this:

function pluck($arr, $key)
{
    $tbr = array();

    foreach ($arr as $val)
    {
        if (is_array($val) && isset($val[$key]))
        {
            $tbr []= $val[$key];
        }
        elseif (is_object($val) && isset($val->$key))
        {
            $tbr [] = $val->$key;
        }
    }

    return $tbr;    
}

Then you could just call it:

$thingsIActuallyWant = pluck($associativeList, 'id');

Additionally, you should avoid passing variables by reference to foreach loops unless you need to.

Upvotes: 1

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