PHP 数组函数 array_filter()

<?php
   function odd($var) {
      return($var & 1);
   }

   function even($var) {
      return(!($var & 1));
   }

   $input1 = array("a"=>1, "b"=>2, "c"=>3, "d"=>4, "e"=>5);
   $input2 = array(6, 7, 8, 9, 10, 11, 12);

   echo "Odd Values:\n";
   print_r(array_filter($input1, "odd"));

   echo "Even Values:\n";
   print_r(array_filter($input2, "even"));
?>