谷歌应用脚本访问第三级 JSON object

Question

When I tried calling hello() on my Google Sheets, it return

Error TypeError: Cannot read property '5. Exchange Rate' of undefined (line 50).

Trigger for the Apps Script is also set up

Criteria	set
Choose which function to run	hello
Which runs at deployment	head
Select event source	From spreadsheet
Select event type	On Open
Failure notification settings	Notify me Daily

JSON OBJECT

{
    "Realtime Currency Exchange Rate": {
        "1. From_Currency Code": "USD",
        "2. From_Currency Name": "United States Dollar",
        "3. To_Currency Code": "SGD",
        "4. To_Currency Name": "Singapore Dollar",
        "5. Exchange Rate": "1.32783000",
        "6. Last Refreshed": "2021-02-26 01:28:59",
        "7. Time Zone": "UTC",
        "8. Bid Price": "1.32783000",
        "9. Ask Price": "1.32783000"
    }
}

Google App Script function

function hello(){
  var usdCurrency = "USD";
  var AV_API_Key = "KEYS";
  var sgdCurrency = "SGD"
  var url = "https://www.alphavantage.co/query?function=CURRENCY_EXCHANGE_RATE&from_currency=" + usdCurrency + "&to_currency=" + sgdCurrency  + "&apikey=" + AV_API_Key;

  var response =  UrlFetchApp.fetch(url);
  var result =  JSON.parse(response.getContentText());
  var currencyPrice = result["Realtime Currency Exchange Rate"]["5. Exchange Rate"];
  
  Logger.log(currencyPrice); // 1.32794000
  Logger.log(typeof(currencyPrice)); // String
  return currencyPrice;
  
}

Update

I set a predefined variable named jsonObj , it is able get the item in the object and place it in the google sheets.

function initTesting(){
  var jsonObj = {
    "Realtime Currency Exchange Rate": {
        "1. From_Currency Code": "USD",
        "2. From_Currency Name": "United States Dollar",
        "3. To_Currency Code": "SGD",
        "4. To_Currency Name": "Singapore Dollar",
        "5. Exchange Rate": "1.32783000",
        "6. Last Refreshed": "2021-02-26 01:28:59",
        "7. Time Zone": "UTC",
        "8. Bid Price": "1.32783000",
        "9. Ask Price": "1.32783000"
    }
};
var getPrice = jsonObj["Realtime Currency Exchange Rate"]["5. Exchange Rate"];
return getPrice;
}

Answer 1

I am not sure whether it is a bug or something but I have work around a solution.

function hello(){
  var usdCurrency = "USD";
  var AV_API_Key = "KEYS";
  var sgdCurrency = "SGD"
  var url = "https://www.alphavantage.co/query?function=CURRENCY_EXCHANGE_RATE&from_currency=" + usdCurrency + "&to_currency=" + sgdCurrency  + "&apikey=" + AV_API_Key;

  var response =  UrlFetchApp.fetch(url);
  var result =  JSON.parse(response.getContentText());
  var currencyPrice = result["Realtime Currency Exchange Rate"]["5. Exchange Rate"];

Even though when I initially logged Logger.log(typeof(currencyPrice)); it showed String on the log. But once I use a String() in the code below, it is able to reflect on the google sheets.

  Logger.log(currencyPrice); // 1.32794000
  Logger.log(typeof(currencyPrice)); // String
  // uses  String() on the currency price
  stringCurrencyPrice = String(currencyPrice)
  return stringcurrencyPrice;
  
}

}