Structs in Dart

Go’s structs are typed collections of fields. They’re useful for grouping data together to form records.

This person struct type has name and age fields.

class Person {
  String name;
  int age;

  Person(this.name, this.age);

  Person.withName(String name) {
    this.name = name;
    this.age = 42;
  }
}

Here’s a constructor that initializes a Person with a given name.

void main() {
  // This syntax creates a new struct
  print(Person("Bob", 20));

  // You can name the fields when initializing a struct
  print(Person("Alice", 30));

  // Omitted fields will be zero-valued (default construction without values)
  var fred = Person("Fred", 0);
  print(fred);

  // Creating a struct with a constructor function
  var ann = Person.withName("Ann");
  print(ann);

  // Access struct fields with a dot
  var s = Person("Sean", 50);
  print(s.name);

  // Darts' structs are mutable
  s.age = 51;
  print(s.age);

  // Anonymous structs
  var dog = {'name': 'Rex', 'isGood': true};
  print(dog);
}

To run the program, just execute the Dart file.

$ dart run your_filename.dart
Person("Bob", 20)
Person("Alice", 30)
Person("Fred", 0)
Person("Ann", 42)
Sean
51
{name: Rex, isGood: true}

Now that we’ve seen how to create and use structs in Dart, let’s move on to more advanced features of the language.

Strings and Runes in Dart

Methods in Dart

Learn X By Example

Title here

Structs in Dart