我对php中的关联数组感到困惑(二维和三维)

Question

我正在学习php.尽管google上有这么多例子,我仍然对实现二维和三维数组感到困惑.简单来说,有人可以用一个例子来解释吗？

Answer 1

对我来说最简单的例子是将SQL表视为多维数组.

该表可能如下所示:

ID | Name | Email
--------------------------
 1 | John | john@email.com
 2 | Jane | jane@email.com

数组可能如下所示:

Array
(
    [0] => Array
        (
            [0] => 1
            [1] => John
            [2] => john@email.com
        )

    [1] => Array
        (
            [0] => 2
            [1] => Jane
            [2] => jane@email.com
        )

)

该表变为数组数组.其中每一行由第一个索引访问,每一列由第二个索引访问.

所以,如果我想得到"简",我会使用$ array [1] [1]

该表的关联数组可能如下所示:

Array
(
    [0] => Array
        (
            [ID] => 1
            [Name] => John
            [Email] => john@email.com
        )

    [1] => Array
        (
            [ID] => 2
            [Name] => Jane
            [Email] => jane@email.com
        )

)

您可以像$ array [1] ["Name"]一样访问"Jane"