android - 如何在Dart中组合循环结果

Question

您好，我有一个简单的for循环，我想将循环结果合并为1个用逗号分隔的字符串

   String loc;
   for(var q=0; q<2; q++){
       userData = res;
       loc = userData[q]['location']; 
       print(loc); //value in first loop is location A value in first second loop is location B i want to combine them on 1 string
      }

Answer 1

如果只想在String中追加

void main() {
  String loc="";
  List<String> locs = ["a","d","B","C"];
   for(var q=0; q<2; q++){
       loc = (loc.length>0? (loc+", ") : loc)+ (locs[q] ?? " "); 
      }

print(loc); 
}