Dart-Lazy-Initialization

Dart 语言中类变量的延迟初始化

类变量存在延迟初始化行为，只有第一次调用时，类变量才执行初始化，即第一次尝试读取它时。

// 类变量存在延迟初始化行为，只有第一次调用时，类变量才执行初始化，即第一次尝试读取它时。
// Class variables are initialized lazily; the initializer of a class variable is executed the first time its getter is invoked—that is, the first time one attempts to read the variable.

class Animal {
  Animal() {
    print("Start Lazy Initialization");
  }
}
Animal animal = new Animal();

void main() {
//   animal; // This statement will call the initializer;
  print("Before Initialization");
  animal;
  print("After Initialization");
}

在 DartPad 运行此代码

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