如何在标准类对象数组(PHP)中返回最小值

Question

我有一个StdClass对象数组，希望返回键"price"的最小值"partner_code"。因此，对于这个例子，我想返回partner_code"AC"，因为它是价格最低的合作伙伴。我试过使用array_reduce，但我不确定我做错了什么。如有任何帮助，我们将不胜感激请注意，我不想整理这个数组。我只想把包含AC的子数组(因为它的价格最低(移到顶部，而不是按价格排序

输入阵列：

Array
(
[0] => stdClass Object
(
[name] => Budget
[partner_code] => BU
[price] => 365.36
[tier] => 1
)
[1] => stdClass Object
(
[name] => Avis
[partner_code] => AV
[price] => 449.71
[tier] => 1
)
[2] => stdClass Object
(
[name] => E-Z
[partner_code] => EZ
[price] => 270.56
[tier] => 2
)
[3] => stdClass Object
(
[name] => Sixt
[partner_code] => SX
[price] => 280.52
[tier] => 2
)
[4] => stdClass Object
(
[name] => Alamo
[partner_code] => AL
[price] => 345.13
[tier] => 2
)
[5] => stdClass Object
(
[name] => Advantage
[partner_code] => AD
[price] => 357.61
[tier] => 2
)
[6] => stdClass Object
(
[name] => Enterprise
[partner_code] => ET
[price] => 364.46
[tier] => 2
)
[7] => stdClass Object
(
[name] => ACE
[partner_code] => AC
[price] => 186.53
[tier] => 3
)
[8] => stdClass Object
(
[name] => Fox
[partner_code] => FX
[price] => 265.25
[tier] => 3
)
[9] => stdClass Object
(
[name] => Payless
[partner_code] => ZA
[price] => 380.47
[tier] => 3
)
[10] => stdClass Object
(
[name] => Dollar
[partner_code] => ZR
[price] => 385.99
[tier] => 3
)
[11] => stdClass Object
(
[name] => Thrifty
[partner_code] => ZT
[price] => 385.99
[tier] => 3
)
[12] => stdClass Object
(
[name] => Silvercar
[partner_code] => SC
[price] => 424.10
[tier] => 3
)
[13] => stdClass Object
(
[name] => National
[partner_code] => NA
[price] => 448.82
[tier] => 3
)
[14] => stdClass Object
(
[name] => Hertz
[partner_code] => HZ
[price] => 487.33
[tier] => 3
)
)

代码：

array_reduce($this->results->companies, function($a,$b) {
echo "Prices: " . $a->price . "<br>";
return $a->price < $b->price ? (string)$a->partner_code : (string)$b->partner_code;
});

Answer 1

usort($array, function($a, $b) {
return ($a->price - $b->price) ;
});
echo $array[0]->partner_code;

Answer 2

如果您真的不想对数组进行排序，而是使用array_reduce，请将数组缩减为其元素之一。然后可以获得该元素的partner_code属性。

例如

array_reduce($this->results->companies, function($lowest, $company) {
// $lowest will be null on the first iteration
return $lowest === null || $company->price < $lowest->price ?
$company : $lowest;
})->partner_code;

Answer 3

此方法不会对整个数组进行排序。它将取出价格最低的子数组，并将其设置为第一个元素。我本可以嵌套一些函数，使其更加紧凑(1行(，但这会损害可读性。

代码：(演示(

$results=[
(object)["name"=>"Budget","partner_code"=>"BU","price"=>"365.36","tier"=>"1"],
(object)["name"=>"Avis","partner_code"=>"AV","price"=>"449.71","tier"=>"1"],
(object)["name"=>"E-Z","partner_code"=>"EZ","price"=>"270.56","tier"=>"2"],
(object)["name"=>"Sixt","partner_code"=>"SX","price"=>"280.52","tier"=>"2"],
(object)["name"=>"Alamo","partner_code"=>"AL","price"=>"345.13","tier"=>"2"],
(object)["name"=>"Advantage","partner_code"=>"AD","price"=>"357.61","tier"=>"2"],
(object)["name"=>"Enterprise","partner_code"=>"ET","price"=>"364.46","tier"=>"2"],
(object)["name"=>"ACE","partner_code"=>"AC","price"=>"186.53","tier"=>"3"],
(object)["name"=>"Fox","partner_code"=>"FX","price"=>"265.25","tier"=>"3"],
(object)["name"=>"Payless","partner_code"=>"ZA","price"=>"380.47","tier"=>"3"],
(object)["name"=>"Dollar","partner_code"=>"ZR","price"=>"385.99","tier"=>"3"],
(object)["name"=>"Thrifty","partner_code"=>"ZT","price"=>"385.99","tier"=>"3"],
(object)["name"=>"Silvercar","partner_code"=>"SC","price"=>"424.10","tier"=>"3"],
(object)["name"=>"National","partner_code"=>"NA","price"=>"448.82","tier"=>"3"],
(object)["name"=>"Hertz","partner_code"=>"HZ","price"=>"487.33","tier"=>"3"]
];
$min=min(array_column($results,'price'));  // find the minimum value
$index=array_search($min,array_column($results,'price'));  // find the index of the subarray containing min value
$pulled=array_splice($results,$index,1);  // extract the subarray and preserve it as $pulled
$new_results=array_merge($pulled,$results);  // set $pulled as first element
var_export($new_results);

好吧，好吧，这是一句话：var_export(array_merge(array_splice($results,array_search(min(array_column($results,'price')),array_column($results,'price')),1),$results));

输出：

array (
0 => 
stdClass::__set_state(array(
'name' => 'ACE',
'partner_code' => 'AC',
'price' => '186.53',
'tier' => '3',
)),
1 => 
stdClass::__set_state(array(
'name' => 'Budget',
'partner_code' => 'BU',
'price' => '365.36',
'tier' => '1',
)),
2 => 
stdClass::__set_state(array(
'name' => 'Avis',
'partner_code' => 'AV',
'price' => '449.71',
'tier' => '1',
)),
3 => 
stdClass::__set_state(array(
'name' => 'E-Z',
'partner_code' => 'EZ',
'price' => '270.56',
'tier' => '2',
)),
4 => 
stdClass::__set_state(array(
'name' => 'Sixt',
'partner_code' => 'SX',
'price' => '280.52',
'tier' => '2',
)),
5 => 
stdClass::__set_state(array(
'name' => 'Alamo',
'partner_code' => 'AL',
'price' => '345.13',
'tier' => '2',
)),
6 => 
stdClass::__set_state(array(
'name' => 'Advantage',
'partner_code' => 'AD',
'price' => '357.61',
'tier' => '2',
)),
7 => 
stdClass::__set_state(array(
'name' => 'Enterprise',
'partner_code' => 'ET',
'price' => '364.46',
'tier' => '2',
)),
8 => 
stdClass::__set_state(array(
'name' => 'Fox',
'partner_code' => 'FX',
'price' => '265.25',
'tier' => '3',
)),
9 => 
stdClass::__set_state(array(
'name' => 'Payless',
'partner_code' => 'ZA',
'price' => '380.47',
'tier' => '3',
)),
10 => 
stdClass::__set_state(array(
'name' => 'Dollar',
'partner_code' => 'ZR',
'price' => '385.99',
'tier' => '3',
)),
11 => 
stdClass::__set_state(array(
'name' => 'Thrifty',
'partner_code' => 'ZT',
'price' => '385.99',
'tier' => '3',
)),
12 => 
stdClass::__set_state(array(
'name' => 'Silvercar',
'partner_code' => 'SC',
'price' => '424.10',
'tier' => '3',
)),
13 => 
stdClass::__set_state(array(
'name' => 'National',
'partner_code' => 'NA',
'price' => '448.82',
'tier' => '3',
)),
14 => 
stdClass::__set_state(array(
'name' => 'Hertz',
'partner_code' => 'HZ',
'price' => '487.33',
'tier' => '3',
)),
)

我认为这是一种更精简的方法，可以产生相同/期望的结果：(演示(

$min=$results[0]->price;  // set initial/default min value
$index=0; // set initial/default index
foreach($results as $i=>$a){
if($a->price<$min){  // if a lower price...
$min=$a->price;  // store new $min
$index=$i;  // stor new $index
}
}
$results=array_merge($results,array_splice($results,$index,1));  // extract lowest and move to front of array
var_export($results);