One of PHP’s less known language constructs is list(), very useful for unpacking indexed arrays. Consider the following simple example denoting its usage:

$record = ['me', '1.800.123.4567', 'me@example.com'];

// Unpack the array into variables, skipping the phone number
list($name, , $email) = $record;

This clean, readable, scalable approach is great for processing data records, unpacking an SQL result row, etc.

Maps / Associative Arrays

As of PHP 7.1.0 list() can now also contain explicit keys, which can be given as arbitrary expressions. Mixing of integer and string keys is allowed; however, elements with and without keys cannot be mixed.

$record = [1, 2, 3, 4, 'a' => '5'];

// Unpack index 1, 3, and 'a' into variables
list(1 => $key1, 'a' => $keya, 3 => $key3) = $record;

Unpacking Maps / Associative Arrays PHP < 7.1.0

There are options: extract() unpacks associative arrays into variables matching the names of their respective keys.

There are both runtime and security issues to consider when using extract() – you will find both discussed in the PHP documentation for the function.

Reasons to favour list() over extract()

• You have control over which indices are extracted
• You have control over the naming of the variables
• list() is a language construct and will be very fast