Question

我有这个数组：

Array
(
    [0] => Array
        (
            [0] => 1
            [1] => a,b,c
        )

    [1] => Array
        (
            [0] => 5
            [1] => d,e,f
        )
)

我希望最终的数组是这样的：

Array
(
    [0] => Array
        (
            [0] => 1
            [1] => a
        )

    [1] => Array
        (
            [0] => 1
            [1] => b
        )

    [2] => Array
        (
            [0] => 1
            [1] => c
        )

    [3] => Array
        (
            [0] => 5
            [1] => d
        )

    [4] => Array
        (
            [0] => 5
            [1] => e
        )

    [5] => Array
        (
            [0] => 5
            [1] => f
        )
)

这就是我所做的：

<?php
    $array = array(array(1,"a,b,c"),array(5,"d,e,f"));
    $temp=array();
    $count = 0;
    foreach($array as $arr){
        $rows = explode(",",$arr[1]);
        foreach($rows as $row){
            $temp[$count] = $arr;
            $temp[$count][1] = $row;
            $count++;
        }
    }
    print_r($temp);
?>

这完全有效，但我想知道是否有更好的方法来做到这一点。当我有大量数据时，这可能会非常慢。

Answer 1

尝试这样......

library(dplyr)
data(iris)    
df <- iris %>%
  group_by(Species) %>%
  mutate(RankSepal = percent_rank(Sepal.Length), 
         RankPetal = percent_rank(Petal.Length))

Answer 2

这是一种功能性方法：

$result = array_merge(...array_map(function(array $a) {
    return array_map(function($x) use ($a) {
        return [$a[0], $x];
    }, explode(",", $a[1]));
}, $array));

Try it online

或者仅仅使用两个循环：

$result = [];
foreach ($array as $a) {
    foreach (explode(",", $a[1]) as $x) {
        $result[] = [$a[0], $x];
    }
}

Try it online

这些时间显示简单的循环结构快了〜8倍。

功能：4.06s user 0.08s system 99% cpu 4.160 total
循环：0.53s user 0.05s system 102% cpu 0.561 total

Answer 3

如果您需要其他方法，

$array = array(array(1, "a,b,c"), array(5, "d,e,f"));
$temp  = [];
array_walk($array, function ($item, $key) use (&$temp) {
    $second = explode(',', $item[1]);
    foreach ($second as $v) {
        $temp[] = [$item[0], $v];
    }
});
print_r($temp);

array_walk - 将用户提供的函数应用于数组的每个成员

以下是demo。

爆炸数组的数据并创建新数组

3 个答案: