根据键对多维数组中的值进行分组

Question

我有以下多维数组:

Array
(
[0] => Array
(
[sname] => florida
[cname] => orlando
)
[1] => Array
(
[sname] => texas
[cname] => dallas
)
[2] => Array
(
[sname] => florida
[cname] => tampa
)
[3] => Array
(
[sname] => ohio
[cname] => columbus
)
)

我该如何获取所有的cname每个'sname的价值?

florida:    orlando, tampa
texas:      dallas
ohio:       columbus

Answer 1

可能有几种方法可以做到这一点。我想到的是这样的:

<?php
$payload = [];
$origin = [
[
'sname' => 'florida',
'cname' => 'orlando'
],
[
'sname' => 'texas',
'cname' => 'dallas'
],
[
'sname' => 'florida',
'cname' => 'tampa'
],
[
'sname' => 'ohio',
'cname' => 'columbus'
]
];

foreach ($origin as $value) {
if (! isset($payload[$value['sname']])) {
$payload[$value['sname']] = '';
}
$payload[$value['sname']] .= (strlen($payload[$value['sname']]) >0?',':'') . $value['cname'];
}
print_r($payload);

干杯!:)

= C =

Answer 2

稍微调整一下Mike的解决方案(https://stackoverflow.com/a/2189916/4954574)，下面将产生我所希望的结果:

$input_arr = array(
array("sname" => "florida", "cname" => "orlando"),
array("sname" => "texas", "cname" => "dallas"),
array("sname" => "florida", "cname" => "tampa"),
array("sname" => "ohio", "cname" => "columbus")
);
foreach ($input_arr as $key => &$entry) {
$level_arr[$entry['sname']][$key] = $entry['cname'];
}
print_r($level_arr);

输出:

Array
(
[florida] => Array
(
[0] => orlando
[2] => tampa
)
[texas] => Array
(
[1] => dallas
)
[ohio] => Array
(
[3] => columbus
)
)