Dart by Example: Lexical Scope

Dart is a lexically scoped language.Loops that declare their variable will have a new version of that variable for each iteration.

1. main() {
2. var functions = [];

4. for (var i = 0; i < 3; i++) {
5. functions.add(() => i);
6. }

8. functions.forEach((fn) => print(fn()));

10. }

1. $ dart lexical_scope.dart
2. 0
3. 1
4. 2

Compared to javascript:

1. var functions = [];

3. for (var i = 0; i < 3; i++) {
4. functions[i] = function() { return i };
5. }

7. functions.forEach(function (fn) { console.log(fn())});

1. $ node lexical_scope.js
2. 3
3. 3
4. 3

by @jryanio | source | license