PHP中高效提取、合并与去重多维数组中的特定值

{
  "themes": [
    {
      "name": "Anchor",
      "categories": "Creative, Portfolio"
    },
    {
      "name": "Agensy",
      "categories": "Creative, Portfolio"
    },
    {
      "name": "Serenity Pro",
      "categories": "One-Page, Multipurpose, Business, Landing Page"
    },
    {
      "name": "Integral Pro",
      "categories": "One-Page, Multipurpose, Business, Landing Page"
    }
  ]
}

<?php

// 模拟获取JSON数据
function curl_get_marketplace_contents() {
    return '{
      "themes": [
        {
          "name": "Anchor",
          "categories": "Creative, Portfolio"
        },
        {
          "name": "Agensy",
          "categories": "Creative, Portfolio"
        },
        {
          "name": "Serenity Pro",
          "categories": "One-Page, Multipurpose, Business, Landing Page"
        },
        {
          "name": "Integral Pro",
          "categories": "One-Page, Multipurpose, Business, Landing Page"
        }
      ]
    }';
}

// 假设这是你的类方法或函数
class ThemeProcessor {
    public function getUniqueCategories() {
        $json = curl_get_marketplace_contents(); // 获取JSON字符串
        $data = json_decode($json, true); // 将JSON解码为关联数组

        $categories = array(); // 初始化一个空数组，用于存储所有分类

        // 遍历 'themes' 数组
        foreach ($data['themes'] as $theme) {
            // 1. 使用逗号将 'categories' 字符串拆分为数组
            $category_items = explode(",", $theme['categories']);

            // 2. 使用 array_map 和 trim 清理每个分类项的空格
            $cleaned_category_items = array_map('trim', $category_items);

            // 3. 使用 array_merge 将当前主题的分类合并到总分类数组中
            // 注意：这里是 $categories = array_merge($categories, $cleaned_category_items);
            // 顺序不影响结果，但习惯上会将待合并的数组放在第二个参数
            $categories = array_merge($categories, $cleaned_category_items);
        }

        // 4. 在所有分类都合并完成后，进行一次性去重
        return array_unique($categories);
    }
}

// 实例化并调用
$processor = new ThemeProcessor();
$uniqueCategories = $processor->getUniqueCategories();

// 输出结果
echo "Unique Categories:\n";
print_r($uniqueCategories);

/*
预期输出：
Unique Categories:
Array
(
    [0] => Creative
    [1] => Portfolio
    [2] => One-Page
    [3] => Multipurpose
    [4] => Business
    [5] => Landing Page
)
*/
?>