I have this array:

我有这个数组:

$datas = array(
    array(
        'id' => '1',
        'country' => 'Canada',
        'cities' => array(
            array(
                'city'  => 'Montreal',
                'lang'   => 'french'
            ),
            array(
                'city'  => 'Ottawa',
                'lang'   => 'english'
            )
        )
    )
);

Question 1:

How can I get the the country name when I have the id ?
I tried: $datas['id'][1] => 'country'

如果我有身份证,我如何获得国家/地区名称?我试过了:$ datas ['id'] [1] =>'country'

Question 2:

How can I loop in the cities when I have the id ?
I tried:

当我有身份证时,如何在城市中循环?我试过了:

foreach ($datas as $data => $info) {
    foreach ($info['cities'] as $item) {
        echo '<li>'.$item['city'].'</li>';
    }
}

Thanks a lot.

非常感谢。

2 个解决方案

#1

You have the ID of the array you want analyse, but your array is structured as a map, meaning that there are no keys in the outer array. You will therefore have to iterate the array first to find the object you are looking for.

您有要分析的数组的ID,但是您的数组是结构化的,这意味着外部数组中没有键。因此,您必须首先迭代数组才能找到您要查找的对象。

While the first approach would be to search for the object that has the ID you are looking for, i suggest you map your arrays with their IDs. To do that, you can use two PHP array functions: array_column and array_combine.

虽然第一种方法是搜索具有您正在寻找的ID的对象,但我建议您使用其ID映射阵列。为此,您可以使用两个PHP数组函数:array_column和array_combine。

array_column can extract a specific field of each element in an array. Since you have multiple country objects, we want to extract the ID from it to later use it as a key.

array_column可以提取数组中每个元素的特定字段。由于您有多个国家/地区对象,因此我们希望从中提取ID以便稍后将其用作关键字。

array_combine takes two arrays with the same size to create a new associative array. The values of the first array will then be used as keys, while the ones of the second array will be used as values.

array_combine采用两个大小相同的数组来创建一个新的关联数组。然后,第一个数组的值将用作键,而第二个数组的值将用作值。

$mappedCountries = array_combine(array_column($datas, 'id'), $datas);

Assuming that the key 1 is stored in the variable $key = 1;, you can afterwards use $mappedCountries[$key]['country'] to get the name of the country and $mappedCountries[$key]['cities'] to get the cities, over which you can then iterate.

假设密钥1存储在变量$ key = 1;中,您可以使用$ mappedCountries [$ key] ['country']来获取国家/地区的名称和$ mappedCountries [$ key] ['cities']获得城市,然后你可以迭代。

#2

if there might be many arrays in $datas and you want to find one by id (or some other key) you can do something like this:

如果$ datas中可能有很多数组,并且你想通过id(或其他一些键)找到一个数组,你可以这样做:

function search($datas, $key, $value) {
    foreach($datas as $data) {
    if ($data[$key] === $value) {
        return $data;   
    }
}

So if you want to find where id = 1 $result = search($datas, 'id', '1'); and then you can get country echo $result['country'] or whatever you need.

所以如果你想找到id = 1 $ result = search($ datas,'id','1')的地方;然后你可以获得country echo $ result ['country']或者你需要的任何东西。

#1