PHP foreach引用&

一、加引用，才能夠改變原數組的值

$oProducts = [
            ['product_id'=>1, 'count'=>3],
            ['product_id'=>2, 'count'=>3],
            ['product_id'=>3, 'count'=>3],
        ];
        foreach($oProducts as &$p)
        {
            $p['order_id'] = 1;
        }
        return json($oProducts);

[{"product_id":1,"count":3,"order_id":1},{"product_id":2,"count":3,"order_id":1},{"product_id":3,"count":3,"order_id":1}]

 

二、若是不加引用，不能改變原數組的值

$oProducts = [
            ['product_id'=>1, 'count'=>3],
            ['product_id'=>2, 'count'=>3],
            ['product_id'=>3, 'count'=>3],
        ];
        foreach($oProducts as $p)
        {
            $p['order_id'] = 1;
        }
        return json($oProducts);

輸出：

[{"product_id":1,"count":3},{"product_id":2,"count":3},{"product_id":3,"count":3}]

 

三、添加引用，至關於

$oProducts = [
            ['product_id'=>1, 'count'=>3],
            ['product_id'=>2, 'count'=>3],
            ['product_id'=>3, 'count'=>3],
        ];

        foreach($oProducts as $key=>$p)
        {
            $oProducts[$key]['order_id'] = 1;
        }

        return json($oProducts);

輸出：

[{"product_id":1,"count":3,"order_id":1},{"product_id":2,"count":3,"order_id":1},{"product_id":3,"count":3,"order_id":1}]