Control Flow

Switch Expression

Pattern Arms

Dart 3 introduces switch expressions with patterns. Each arm yields a value, and _ is the wildcard.

Program

Play the program to map an integer code to a label.

switch_pattern.dart 
void main() {
  Object code = 2;
  var label = switch (code) {
    1 => 'one',
    2 => 'two',
    _ => 'many',
  };
  print(label);
}
switch expression `switch (x) { ... }` evaluates to a value.
pattern arm `1 =>`, `2 =>`, etc. match constant patterns.
wildcard `_` matches anything not handled above.