PHP 陣列相加和array_merge的差別

PHP數組處理強大的功能導致了各種資料處理函數。

其中數組相加以及array_merge讓筆者踩了個小坑。

一、請看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輸出：

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

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

結論：

$a + $b  

        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輸出：

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

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

結論：

$a + $b 增量覆蓋

array_merger($a,$b) $b優先替換掉$a

以上就介紹了PHP 數組相加和array_merge的區別，包括了方面的內容，希望對PHP教程有興趣的朋友有所幫助。