Question

Python has syntactically sweet list comprehensions:

S = [x**2 for x in range(10)]
print S;
[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

In PHP I would need to do some looping:

$output = array();
$Nums = range(0,9);

foreach ($Nums as $num) 
{
    $out[] = $num*=$num;
}
print_r($out);

to get:

Array
(
[0] => 0
[1] => 1
[2] => 4
[3] => 9
[4] => 16
[5] => 25
[6] => 36
[7] => 49
[8] => 64
[9] => 81
)

Is there anyway to get a similar list comprehension syntax in PHP? Is there anyway to do it with any of the new features in PHP 5.3?

Thanks!

Answer 1

Maybe something like this?

$out=array_map(function($x) {return $x*$x;}, range(0, 9))

This will work in PHP 5.3+, in an older version you’d have to define the callback for array_map separately

function sq($x) {return $x*$x;}
$out=array_map('sq', range(0, 9));