PHP：多维数组中的 Foreach [重复]答案

【问题标题】：PHP: Foreach in a multidimensional array [duplicate]PHP：多维数组中的 Foreach [重复]
【发布时间】：2018-03-01 13:08:49
【问题描述】：

得到了一个学校的任务来制作一个多维数组。

<?php
$cars = array( 
        "car1" => array (   
            "brand" => 'BMW',
            "license" => '30-KL-PO',    
            "price" => 10000
            ),

        "car2" => array (
           "brand" => 'Mercedes',
           "license" => '51-ZD-ZD',
           "price" => 20000
        ),

        "car3" => array (
           "brand" => 'Maserati',
           "license" => 'JB-47-02',
           "price" => 30000
        )
     );

foreach($carss as $car){
echo $car['car1']['brand'] . $car['car1']['brand'] . "<br>";
}

?>

我需要使用 foreach 显示所有汽车的品牌和许可证。我只用 car1 进行了尝试，但出现错误：未定义索引：car1。

我知道如何只使用 echo 来显示它，但我的作业说我必须使用 foreach。

【问题讨论】：

标签： php arrays multidimensional-array foreach

【解决方案1】：

将循环更改为

foreach($carss as $key => $car){
   echo $key ." ". $car['brand'] . "<br>";
}

【讨论】：

【解决方案2】：

离你不远了：

<?php
$cars = array( 
        "car1" => array (   
            "brand" => 'BMW',
            "license" => '30-KL-PO',    
            "price" => 10000
            ),

        "car2" => array (
           "brand" => 'Mercedes',
           "license" => '51-ZD-ZD',
           "price" => 20000
        ),

        "car3" => array (
           "brand" => 'Maserati',
           "license" => 'JB-47-02',
           "price" => 30000
        )
     );

foreach($cars as $car)
    printf("%-10s %s\n",  $car['brand'], $car['license']);

输出：

BMW        30-KL-PO
Mercedes   51-ZD-ZD
Maserati   JB-47-02

使用键定位来自$cars 的单个值：

echo $cars['car1']['brand'];

输出：

BMW

【讨论】：

【解决方案3】：

你可以这样做

<?php
$cars = array( 
    "car1" => array (   
        "brand" => 'BMW',
        "license" => '30-KL-PO',    
        "price" => 10000
    ),
    "car2" => array (
        "brand" => 'Mercedes',
        "license" => '51-ZD-ZD',
        "price" => 20000
    ),
    "car3" => array (
        "brand" => 'Maserati',
        "license" => 'JB-47-02',
        "price" => 30000
    )
);
$result = []; // blank array to store result 
foreach($cars as $key => $val):
$result[$key]["brand"] = $val["brand"]; 
$result[$key]["license"] = $val["license"]; 
endforeach;
#echo "<pre>";
#print_r($result);
?>

【讨论】：