PHP数组结构变化

Question

这不应该让我感到困惑，但我正在寻求解决：

array:3 [▼
  "subject" => array:2 [▼
        0 => "math"
        1 => "english"
  ]
 "grade" => array:2 [▼
      0 => "a"
      1 => "b"
  ]
  "received" => array:2 [▼
      0 => "2017"
      1 => "2016"
  ]
]

到这个：

array:2 [▼
  "0" => array:3 [▼
    "subject" => "math"
    "grade" => "a"
    "received" => "2017"
  ]
  "1" => array:3 [▼
    "subject" => "english"
    "grade" => "b"
    "received" => "2016"
  ]
]

尝试以几种不同的方式循环遍历，但似乎从未获得我想要的结果，任何帮助将不胜感激！

Answer 1

$keys = array_keys($array);
$result = array_map(
    function (...$values) use ($keys) { return array_combine($keys, $values); }, 
    ...array_values($array)
);

本质上是这样，但重复性较低：

array_map(
    function ($subject, $grade, $received) {
        return [
            'subject' => $subject,
            'grade' => $grade, 
            'received' => $received
        ];
    },
    $array['subject'],
    $array['grade'],
    $array['received']
)

有关更多说明，请参见手册中的array_map和...

Answer 2

简单版本：

$arr1 = array(...);
$arr2 = array();

foreach ($arr1 as $k => $v) {
    foreach ($v as $x => $y) {
        $arr2[$x][$k] = $y;
    }
}

但是，如果数组元素不存在，则应添加条件，然后创建条件，否则可能会出现错误，具体取决于您的PHP配置。