Question

我有这样的数组：

$listRest = 
Array
([restaurants] => Array
        (
            [0] => Array
                (
                    [restaurant] => Array
                        (
                            [name] => Pipe and Puff
                            [location] => Array
                                (
                                    [city_id] => 74
                                )
                            [average_cost_for_two] => 150000
                            [user_rating] => Array
                                (
                                    [aggregate_rating] => 3.8
                                )
                        )
                )

        [1] => Array
            (
                [restaurant] => Array
                    (
                        [location] => Array
                        (
                                [city_id] => 74
                            )
                        [average_cost_for_two] => 300000
                        [user_rating] => Array
                            (
                                [aggregate_rating] => 3.4
                            )
                    )
            )

我想找到“average_cost_for_two”和“aggregate_rating”的最小值，但是它说“max（）：当只给出一个参数时，它必须是一个数组”

这是我的代码

$rest = $listRest['restaurants'];
foreach($listRest as $value)
{
  $price = $value['restaurant']['average_cost_for_two'];
  $rating = $value['restaurant']['user_rating']['aggregate_rating'];
}
echo max($price)."</br>.";
echo max($rating);

Answer 1

您应该初始化数组以将价格和评级值放在那里。此外，当您添加另一个值时，您应该放入另一个数组元素。 Max函数从数组中选择最高值。

$rest = $listRest['restaurants'];
$price = [];
$rating = [];
foreach($rest as $value)
{
  $price[] = $value['restaurant']['average_cost_for_two'];
  $rating[] = $value['restaurant']['user_rating']['aggregate_rating'];
}
echo max($price)."</br>.";
echo max($rating);

Answer 2

如果我没有理解你的问题，你可以尝试分别分配这个$price[]和$rating[]的每个价格和评级。

$price = $rating = [];
$rest = $listRest['restaurants'];
foreach($listRest as $value)
{
  $price[] = $value['restaurant']['average_cost_for_two'];   // see the change here
  $rating[] = $value['restaurant']['user_rating']['aggregate_rating']; // see the change here
}
echo max($price)."</br>.";
echo max($rating);

echo min($price)."</br>.";
echo min($rating);

Answer 3

$ rest = $ listRest ['restaurants'];

foreach（$ listRest as $ value）

应该是

$rest = $listRest['restaurants']; 

foreach($rest as $value)

$ price = $ value ['restaurant'] ['average_cost_for_two'];

$ rating = $ value ['restaurant'] ['user_rating'] ['aggregate_rating'];

将覆盖以前的$ price和$ rating值，因此，max（$ price）和max（$ rating）将无效。
此外，在forloop中定义了$ price和$ rating，它们将无法在其外部访问。
- 因此，请将forloop之外的$ price和$ rating实例化为$price[]和$rating[]。

echo max（$ price）。“。”;

echo max（$ rating）;

Max函数适用于数组，因此在forloop中你必须将循环获得的每个值推送（插入）分别为$ price和$ rating，

$price[] = $value['restaurant']['average_cost_for_two'];
$rating[] = $value['restaurant']['user_rating']['aggregate_rating'];

Answer 4

你只需要将所有数据放在一个数组中，然后在其上执行max（）。我创建了一个实时PHP脚本来纠正您的代码：get max and min value from child multidimensional php

从子多维php获取最大值和最小值

4 个答案: