问如何使用php引用具有键值对的json数组

EN

<?php
 // Identify the content as json
header("Content-Type: application/json; charset=UTF-8");

// get the contents of the JSON file
$data = file_get_contents("php://input");

//normalize the json in order to be properly decoded

$start=strpos($data,':',strpos($data,'response_data'));
$get=substr($data,$start+1,strrpos($data,'"')-$start);
$data=str_replace($get,trim(trim($get),'"'),$data);

//decode JSON data to PHP array
$content = json_decode($data, true);

//Fetch the details of customer

$Cust_Fname = $content['first_name'];
$Cust_Lname = $content['last_name'];
$Cust_Email = $content['email'];
$Street_Address = $content['address'];
$City = $content['city'];
$State = $content['state'];
$Country = $content['country'];
$Postal_Code = $content['zip_code'];

//also fetch the appended "array" of key/value fields...
$Response_AgeKey = $content['reponse_data'][0]['key'];
$Response_GenderKey = $content['reponse_data'][1]['key'];
$Response_IncomeKey = $content['reponse_data'][2]['key'];
$Response_CityKey = $content['reponse_data'][3]['key'];
$Response_StateKey = $content['reponse_data'][4]['key'];
$Response_CountryKey = $content['reponse_data'][5]['key'];
$Response_Age = $content['reponse_data'][0]['value'];
$Response_Gender = $content['reponse_data'][1]['value'];
$Response_Income = $content['reponse_data'][2]['value'];
$Response_City = $content['reponse_data'][3]['value'];
$Response_State = $content['reponse_data'][4]['value'];
$Response_Country = $content['reponse_data'][5]['value']

?>

{
  "address": "4 Ficticious Ave",
  "city": "Miami",
  "country": "United States",
  "email": "jane_doe@gmail.com",
  "first_name": "Jane",
  "last_name": "Doe",
  "state": "FL",
  "zip_code": "03423",
  "response_data": [
    {
      "key": "7122",
      "value": "37-52"
    },
    {
      "key": "7123",
      "value": "Female"
    },
    {
      "key": "7124",
      "value": "$35,000 to $50,000 USD"
    },
    {
      "key": "6176",
      "value": "Miami"
    },
    {
      "key": "6177",
      "value": "FL"
    },
    {
      "key": "6179",
      "value": "United States"
    }
  ]
}