PHP-filter arrays using callback functions-php Tutorial

PHP --- filter arrays using callback functions & lt; div & gt; & lt ;? Php returns functionodd ($ var) {return ($ var % 21) if it is an odd number;} returns functioneven ($ var) if it is an even number) {return ($ var % 20);} $ nums1 PHP --- use the callback function to filter arrays

  1, "222" => 2, "333" => 3, "444" => 4, "555" => 5); $ nums2 = $ nums1; echo"
"; Echo" Odd: \ n "; // callback function. if true is returned, the data in $ array1 is assigned to the original array. The key remains unchanged in print_r (array_filter ($ nums1, "odd"); echo"
"; Echo"
"; Echo" Even: \ n "; print_r (array_filter ($ nums2," even "); echo"
";?>