如何构建嵌套关联数组

Question

我想构建一个深度嵌套的关联数组，但是我不知道构建它的规则。我有这个理论数组：

-one
-two
-three
-four
    -one
    -two
    -three
    -four
-five
-six
-seven
-eight
-nine
    -one
    -two            
    -three 
            -one
            -two
            -three
            -four
            -five
            -six

我尝试将其表示为 PHP 关联数组：

$associative = array(
'one' => 'one-1',
'two' => 'two-2',
'three' => 'three-3',
'four' => 'four-4'
(
    'one' => 'one-four-1',
    'two' => 'two-four-2',
    'three' => 'three-four-3',
    'four' => 'four-four-4'
)
'five' => 'five-5',
'six' => 'six-6',
'seven' => 'seven-7',
'eight' => 'eight-8',
'nine' => 'nine-9'
(
    'one' => 'one-nine-1',
    'two' => 'two-nine-2',          
    'three' => 'three-nine-3' 
(   
        'one' => 'one-nine-three-1',
        'two' => 'two-nine-three-2',
        'three' => 'three-nine-three-3',
        'four' => 'four-nine-three-4',
        'five' => 'five-nine-three-5',
        'six' => 'six-nine-three-6'
))
);
$keys = array_values($associative);
echo $keys[0];

当我尝试执行php代码片段时，出现了以下错误：

解析错误：在C:\wamp\www\array.php的第7行，意外的 '('，期望 ')'。

所以我的问题是，编写此类数组的正确方式是什么？我希望添加更多子元素时应该遵循什么规则？

注：在我的虚拟数组中，数字4有四个子元素，数字9有三个子元素，数字3有六个子元素。无论如何，我希望你能理解在这个虚拟数组中“子元素”的含义。

- Gandalf

Answer 1

子数组是顶层数组元素的实际值，您需要使用array()来初始化它们：

$associative = array(
    'one' => 'one-1',
    'two' => 'two-2',
    'three' => 'three-3',
    'four' => array(
        'one' => 'one-four-1',
        'two' => 'two-four-2',
        'three' => 'three-four-3',
        'four' => 'four-four-4'
    ),
    'five' => 'five-5',
    'six' => 'six-6',
    'seven' => 'seven-7',
    'eight' => 'eight-8',
    'nine' => array(
        'one' => 'one-nine-1',
        'two' => 'two-nine-2',          
        'three' => array(   
            'one' => 'one-nine-three-1',
            'two' => 'two-nine-three-2',
            'three' => 'three-nine-three-3',
            'four' => 'four-nine-three-4',
            'five' => 'five-nine-three-5',
            'six' => 'six-nine-three-6'
        ),
    ),
);

请注意，我还在每个闭合的)后面添加了,，因为，正如我所说，这些数组是父数组元素的值。

- Jeroen

Answer 2

$associative = array(
  'one' => 'one-1',
  'two' => 'two-2',
 'three' => 'three-3',
 'four' => array(
   'one' => 'one-four-1',
    'two' => 'two-four-2',
    'three' => 'three-four-3',
   'four' => 'four-four-4'
 ),
  'five' => 'five-5',
  'six' => 'six-6',
  'seven' => 'seven-7',
  'eight' => 'eight-8',
  'nine' => array(
    'one' => 'one-nine-1',
    'two' => 'two-nine-2',          
    'three' => array(
        'one' => 'one-nine-three-1',
        'two' => 'two-nine-three-2',
        'three' => 'three-nine-three-3',
        'four' => 'four-nine-three-4',
        'five' => 'five-nine-three-5',
        'six' => 'six-nine-three-6'
    )
  )
);
print_r($associative);

- Brian