如何裁剪期货 期货的主体 在没有错误的飞镖扑打中

Question

我想将下面的代码变成：

Future<List> fetchPrices() async {details in code below} 

没有错误。

要更改的代码在这里：

  Future<void> main(List<String> arguments) async {
  Map<String, num> quotes = await Forex.fx(
  quoteProvider: QuoteProvider.yahoo,
  base: 'USD',
  quotes: <String>['EUR', 'JPY']);
  print('Number of quotes retrieved: ${quotes.keys.length}.');
  print('Exchange rate USDEUR: ${quotes['USDEUR']}.');
  print('Exchange rate USDJPY: ${quotes['USDJPY']}.');
  quotes = await Forex.fx(
  quoteProvider: QuoteProvider.ecb,
  base: 'JPY',
  quotes: <String>['EUR', 'USD']);
  print('Number of quotes retrieved: ${quotes.keys.length}.');
  print('Exchange rate JPYEUR: ${quotes['JPYEUR']}.');
  print('Exchange rate JPYUSD: ${quotes['JPYUSD']}.');
  }
enter code here

Answer 1

您必须具有return语句。