<?php 
    // 此处填写你在控制台-应用管理-创建应用后获取的AK
    $ak = '您的AK';
    
    // 发起一个http get请求，并返回请求的结果
    // $url字段为请求的地址
    // $param字段为请求的参数
    function request_get($url = '', $param = array()) {
        if (empty($url) || empty($param)) {
            return false;
        }
        
        $getUrl = $url . "?" . http_build_query($param);
        $curl = curl_init(); // 初始化curl
        curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false); // 跳过证书检查   
        curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, 2); // 从证书中检查SSL加密算法是否存在
        curl_setopt($curl, CURLOPT_URL, $getUrl); // 抓取指定网页
        curl_setopt($curl, CURLOPT_TIMEOUT, 1000); // 设置超时时间1秒
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1); // curl不直接输出到屏幕
        curl_setopt($curl, CURLOPT_HEADER, 0); // 设置header
        $data = curl_exec($curl); // 运行curl

        if (!$data) {
            print("an error occured in function request_get(): " . curl_error($curl) . "\n");
        }

        curl_close($curl);
        
        return $data;
    }

    // 请求地址
    $url = 'https://api.map.baidu.com/api_region_search/v1/';
    
    // 构造请求参数
    $param['keyword']   = '山东';
    $param['sub_admin']   = '2';
    $param['ak']   = $ak;

    $res = request_get($url, $param);

    // 将原始返回的结果打印出来
    print("请求的原始返回结果为:\n");
    print($res . "\n");
?>

{
    "status": 0,
    "data_version": "20220722",
    "result_size": 1,
    "districts": [
      {
        "code": "",
        "name": "山东省",
        "level": 1,
        "districts": [
          {
            "code": "",
            "name": "日照市",
            "level": 2,
            "districts": []
          },
          {
            "code": "",
            "name": "青岛市",
            "level": 2,
            "districts": []
          },
          {
            "code": "",
            "name": "济南市",
            "level": 2,
            "districts": []
          },
          {
            "code": "",
            "name": "潍坊市",
            "level": 2,
            "districts": []
          },
          {
            "code": "",
            "name": "济宁市",
            "level": 2,
            "districts": []
          },
          {
            "code": "",
            "name": "菏泽市",
            "level": 2,
            "districts": []
          },
          {
            "code": "",
            "name": "烟台市",
            "level": 2,
            "districts": []
          },
          {
            "code": "",
            "name": "滨州市",
            "level": 2,
            "districts": []
          },
          {
            "code": "",
            "name": "德州市",
            "level": 2,
            "districts": []
          },
          {
            "code": "",
            "name": "淄博市",
            "level": 2,
            "districts": []
          },
          {
            "code": "",
            "name": "枣庄市",
            "level": 2,
            "districts": []
          },
          {
            "code": "",
            "name": "泰安市",
            "level": 2,
            "districts": []
          },
          {
            "code": "",
            "name": "聊城市",
            "level": 2,
            "districts": []
          },
          {
            "code": "",
            "name": "威海市",
            "level": 2,
            "districts": []
          },
          {
            "code": "",
            "name": "临沂市",
            "level": 2,
            "districts": []
          },
          {
            "code": "",
            "name": "东营市",
            "level": 2,
            "districts": []
          }
        ]
      }
    ]
  }