如何将 dart 中的 2 个或更多地图组合/合并为 1 个地图？ 例如我有类似的东西：

 var firstMap = {"1":"2"};
 var secondMap = {"1":"2"};
 var thirdMap = {"1":"2"};

I want:

 var finalMap = {"1":"2", "1":"2", "1":"2"};

您可以使用addAll的方法Map object

var firstMap = {"1":"2"};
var secondMap = {"2":"3"};

var thirdMap = {};

thirdMap.addAll(firstMap);
thirdMap.addAll(secondMap);

print(thirdMap);

Or

var thirdMap = {}..addAll(firstMap)..addAll(secondMap);

Update

从 dart sdk 2.3 开始 您可以使用扩展运算符...

final firstMap = {"1":"2"};
final secondMap = {"2":"3"};

final thirdMap = {
   ...firstMap,
   ...secondMap,
};