【PHP】compact関数で連想配列を作成する

compact ( mixed $varname1 [, mixed $... ] ) : array

$apple  =  10;
$orange =  30;
$banana = 100;
$melon  = 200;
$arr  = compact('apple', 'orange', 'banana');
$arr += compact('melon');

print_r($arr);

Array
(
    [apple] => 10
    [orange] => 30
    [banana] => 100
    [melon] => 200
)