Check out example codes for "dart combine maps". It will help you in understanding the concepts better.

Code Example 1

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

final thirdMap = {
   ...firstMap,
   ...secondMap,
};
//thirdMap: {"1":"2",
//			 "2":"3"}

Learn ReactJs, React Native from akashmittal.com