Question

我只想从这个分组数组：

["2019 Honda Civic" => "Sedan", 
 "Maruti Suzuki Baleno" => "Hatchback",  
 "Rolls-Royce Phantom" => "Sedan"]

对此

["Sedan" => ["2019 Honda Civic", "Rolls-Royce Phantom"], 
 "Hatchback" => ["Maruti Suzuki Baleno"]]

<?php
function groupByType($cars) {
       return; 
}

$cars= ["2019 Honda Civic" => "Sedan", "Maruti Suzuki Baleno" => "Hatchback",  "Rolls-Royce Phantom" => "Sedan"];
$groups = groupByType($cars);
var_dump($groups);

Answer 1

可能还有array_*个函数的组合也可以实现此目的，但是您可以循环数组并翻转值-按旧值（新键）分组，如下所示。

$result = [];
foreach ($array as $k=>$v) {
    if (!isset($result[$v]))
        $result[$v] = [$k];
    else 
        $result[$v][] = $k;
}
return $result;

https://example.com/website/%上的实时演示

Answer 2

您可以轻松地使用array_flip()翻转阵列，然后做一些整理工作。在此处查看演示：https://eval.in/1091512

$cars= ["2019 Honda Civic" => "Sedan", "Maruti Suzuki Baleno" => "Hatchback",  "Rolls-Royce Phantom" => "Sedan"];

$groups = array_flip($cars);

foreach ($groups as $g => $c)
    $groups[$g] = implode(", ", array_keys($cars, $g));

我想在此关联数组中按汽车类型对它们进行分组。-PHP

2 个答案: