Flutter 入门指南之 Dart 语言基础介绍

var name = 'Alice'; // 自动推断类型
final age = 30; // 不可变的变量
const pi = 3.14; // 编译时常量
List<int> numbers = [1, 2, 3];
Map<String, dynamic> person = {'name': 'Bob', 'age': 25};

void sayHello(String name) {
  print('Hello, $name!');
}
int square(int num) {
  return num * num;
}
if (condition) {
  // 执行语句块
} else {
  // 执行语句块
}
for (var i = 0; i < 5; i++) {
  print(i);
}
while (condition) {
  // 执行语句块
}

class Person {
  String name;
  int age;
  Person(this.name, this.age);
  void sayHello() {
    print('Hello, I am $name!');
  }
}
var person = Person('Alice', 30);
person.sayHello();

Future<String> fetchData() async {
  await Future.delayed(Duration(seconds: 2));
  return 'Data fetched!';
}
void main() async {
  print('Fetching data...');
  var data = await fetchData();
  print(data);
}