phparrayslist-comprehensionhigher-order-functionslanguage-comparisons

Does PHP have an equivalent to Python's list comprehension syntax?

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!

Solution

  • 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));