PHP中如何读取交错XML子节点？获取指定分类平均评分

Hey there! Let's break down how to grab those wifi and location average ratings from your new XML structure. The key issue here is that you're dealing with repeating <subcategoryRating> nodes, so we can't just reference them directly by path—we need to loop through and filter for the categories you care about.

First, Let's Assume Your XML Structure Looks Something Like This #

(Adjust this to match your actual API response if needed):

<business>
  <subcategoryRating>
    <subcategoryRating>
      <name>wifi</name>
      <averageRating>4.2</averageRating>
    </subcategoryRating>
    <subcategoryRating>
      <name>location</name>
      <averageRating>4.7</averageRating>
    </subcategoryRating>
    <!-- Additional subcategory nodes here -->
  </subcategoryRating>
</business>

Step-by-Step Code Implementation #

Here's how to extract the ratings into separate variables using simplexml_load_file:

// Load the XML data as before
$xml = simplexml_load_file('your-api-endpoint.xml');

// Initialize variables to hold your target ratings
$wifiRating = null;
$locationRating = null;

// Access the nested list of subcategoryRating nodes
$allSubcategoryRatings = $xml->business->subcategoryRating->subcategoryRating;

// Loop through each rating node to find matches
foreach ($allSubcategoryRatings as $ratingNode) {
    // Convert the category name to a string (critical for comparison)
    $categoryName = (string)$ratingNode->name;
    
    // Check which category we're dealing with and assign the rating
    if ($categoryName === 'wifi') {
        $wifiRating = (float)$ratingNode->averageRating;
    } elseif ($categoryName === 'location') {
        $locationRating = (float)$ratingNode->averageRating;
    }
}

// Now you can use these variables elsewhere in your code
echo "Wifi Average Rating: " . $wifiRating . "\n";
echo "Location Average Rating: " . $locationRating . "\n";

Important Notes #

• Adjust for Attribute-Based Categories: If your XML uses attributes instead of child nodes for category names (e.g., <subcategoryRating name="wifi">), replace (string)$ratingNode->name with (string)$ratingNode['name'].
• Type Casting: Using (string) and (float) ensures we convert the SimpleXMLElement objects to native PHP types, avoiding unexpected behavior when using the values later.
• Fallback Values: If a category might be missing from the XML, the variables will stay null—you can set default values (like 0 or 'N/A') if needed.

内容的提问来源于stack exchange，提问作者Andreas