How Can I Efficiently Retrieve Specific Keys from a Multidimensional Array in PHP?

Retrieve Specific Array Keys in a Multidimensional Array Without Iteration

In PHP, accessing data from multidimensional arrays can often require tedious looping. However, there are built-in PHP functions that allow you to extract specific keys efficiently.

Extraction Using array_column

For PHP 5.5 and above, the simplest solution is to use array_column:

$ids = array_column($users, 'id');

This function extracts the values corresponding to the specified key ('id') and returns an array.

Alternative Extraction Methods

If PHP 5.5 or higher is not supported, there are alternative approaches:

Anonymous Function:

$ids = array_map(function ($ar) {return $ar['id'];}, $users);

This method uses array_map with an anonymous function that returns the value for the 'id' key.

create_function:

$ids = array_map(create_function('$ar', 'return $ar["id"];'), $users);

This pre-PHP 5.3 syntax creates an anonymous function using create_function. It is less efficient than the other methods.

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