<?php$array = array_flip ( [ "a" => 1, "b" => 1, "c" => 2, ] // array $array);?>
$array = [ 1 => 'b', 2 => 'c',]
[ 1 => 'b', 2 => 'c',]
#1
array_flip
(["a" => 1, "b" => 2, "c" => 3])
#2
(["a" => 1, "b" => 1, "c" => 2])