我有3组2d数组，它们的元素编号不同？一个是需要作为关键字（日期和时间）的数组，以便与其他两个数组进行比较。另外两个数组必须按顺序排列。对于空的行，我希望设置为-9999。
第一个阵列：
Array (
[0] => Array
(
[0] => 01/7/2013
[1] => 12.00 a.m
)
[1] => Array
(
[0] => 01/7/2013
[1] => 12.01 a.m
)
[2] => Array
(
[0] => 01/7/2013
[1] => 12.02 a.m
)
)
对于第二个阵列：
Array(
[0] => Array
(
[0] => 01/7/2013
[1] => 12.01 a.m
[2] => 9.02
)
)
对于第三个阵列：
Array(
[0] => Array
(
[0] => 01/7/2013
[1] => 12.00 a.m
[2] => 1.23
[3] => 6.1
)
[1] => Array
(
[0] => 01/7/2013
[1] => 12.02 a.m
[2] => 1.75
[3] => 1.75
)
)
我需要输出为：
Array(
[0] => Array
(
[0] => 01/7/2013
[1] => 12.00 a.m
[2] => -9999
[3] => 1.23
[4] => 6.1
)
[1] => Array
(
[0] => 01/7/2013
[1] => 12.01 a.m
[2] => 9.02
[3] => -9999
[4] => -9999
)
[2] => Array
(
[0] => 01/7/2013
[1] => 12.02 a.m
[2] => -9999
[3] => 1.75
[4] => 1.75
)
)
$arr = array_merge($arr1, $arr2, $arr3);
$out = array();
$cnt = 0;
foreach ($arr as $key => $value){
$date = explode('/', $value[0]);//Change date format
$dex = strtotime($date[1].'/'.$date[0].'/'.$date[2].' '.$value[1]);
$head = (array_key_exists($dex, $out)) ? $out[$dex] : array_slice($value, 0, 2);
$out[$dex] = array_merge($head, array_slice($value, 2));
$cnt = ($cnt > count($out[$dex])) ? $cnt : count($out[$dex]);
}
$out = array_map(function ($e) use ($cnt){
return array_pad($e, $cnt, '-9999');
}, array_values($out));
print_r($out);
这适用于PHP 5.3及更高版本。对于旧版本的PHP，可以用以下内容替换array_map函数：
foreach ($out as $key => $value){
$res[] = array_pad($value, $cnt, -9999);
}
print_r($res);
新版本（适用于PHP 5.3或更高版本）：
$template = array();
array_walk($arr1, function (&$e, $k) use (&$template){
$date = explode('/', $e[0]);
$dex = strtotime($date[1].'/'.$date[0].'/'.$date[2].' '.$e[1]);
$template[$dex][0] = '-9999';
});
$arr1 = array_combine(array_keys($template), $arr1);
$out = array();
$data = array($arr2, $arr3);
foreach ($data as $key => $value){
foreach ($value as $key2 => $value2){
$date = explode('/', $value2[0]);//Change date format
$dex = strtotime($date[1].'/'.$date[0].'/'.$date[2].' '.$value2[1]);
$out[$key][$dex] = array_slice($value2, 2);
}
$out[$key] += array_diff_key($template, $out[$key]);
foreach ($out[$key] as $key2 => $value2){
$arr1[$key2] = array_merge($arr1[$key2], $value2);
}
}
print_r(array_values($arr1));