Flutter Dart Merge Two List

In Dart List are used as Array of items. In today's tutorial we will concat two different list into single list. There are 2 different ways to marge a List in dart. First is with List.addAll() method and other is with spread(...) three dot operator.

Flutter Dart Merge Two List

1. Marge List with addAll() method in Dart:

List.addAll() method will append all the other list elements at the end of current list. One more important thing is list in which we are merging should be growable.

Syntax:

void addAll(Iterable<String> iterable)

Code example:

void main() {
  
  List<String> list1 = <String>['One', 'Two', 'Three'];

  List<String> list2 = <String>['O', 'T', 'T'];
  
  list1.addAll(list2);
  
   print(list1);
  
}

Output:

2. Marge List with Spread Operator in Dart:

Spread operator known as Tree Dotted Joint operator in programming languages. It is used to combine two list into new list.

Code example:

void main() {
  
  List<String> list1 = <String>['One', 'Two', 'Three'];

  List<String> list2 = <String>['O', 'T', 'T'];
  
  List<String> list3 = [...list1, ...list2];
  
  List<num> numList1 = [10.11, 9.22, 8.33];

  List<num> numList2 = [7.01, 6, 5];
  
  List<num> numList3 = [...numList1, ...numList2];
  
   print(list3);
  
   print(numList3);
  
}

Output: