Differences between PHP array addition and array_merge

: This article mainly introduces the differences between PHP array addition and array_merge. if you are interested in PHP Tutorial, please refer to it. PHP array processing has powerful functions that result in various data processing functions.

The array addition and array_merge let the author step on a small pitfall.

1. see demo1:

        public function action_test54(){                $a = array(                        '0'=>1567,                        '1'=>1568,                        '2'=>1569,                        '3'=>1570,                );                $b = array(                        '1'=>1571,                        '2'=>1572,                        '3'=>1573,                        '4'=>1574                );                d($a + $b);                dd(array_merge($a,$b));        }

Demo1 output:

array(5) (    0 => integer 1567    1 => integer 1568    2 => integer 1569    3 => integer 1570    4 => integer 1574)

array(8) (    0 => integer 1567    1 => integer 1568    2 => integer 1569    3 => integer 1570    4 => integer 1571    5 => integer 1572    6 => integer 1573    7 => integer 1574)

Conclusion:

$ A + $ B incremental coverage

Array_merge ($ a, $ B) merge

II. Demo2

        public function action_test54(){                $a = array(                        'a'=>1567,                        'b'=>1568,                        'c'=>1569,                        'd'=>1570,                );                $b = array(                        'b'=>1571,                        'c'=>1572,                        'd'=>1573,                        'e'=>1574                );                d($a + $b);                dd(array_merge($a,$b));        }

Demo2 output:

array(5) (    "a" => integer 1567    "b" => integer 1568    "c" => integer 1569    "d" => integer 1570    "e" => integer 1574)

array(5) (    "a" => integer 1567    "b" => integer 1571    "c" => integer 1572    "d" => integer 1573    "e" => integer 1574)

Conclusion:

$ A + $ B incremental coverage

Array_merger ($ a, $ B) $ B is replaced with $ a first.

The above introduces the differences between PHP array addition and array_merge, including the content, hope to be helpful to friends who are interested in PHP tutorials.