Question

问题：

我是否正在观察TypeScript的预期行为？
我是否正在观察ECMAScript 6的预期行为？
是否有一种简单的方法可以走回继承层次结构来处理“myStatic”＃39;每个级别的数组？我怎么知道什么时候停止？

描述：使用TypeScript时，派生类和静态属性似乎有一些有趣的行为。

class MyBase {
    static myStatic = [];
}

class MyDerived extends MyBase {}

MyBase.myStatic = ['one', 'two', 'three']

class MyDerived2 extends MyBase {}

document.body.innerHTML += "<b>MyDerived.myStatic:</b>&nbsp;" + JSON.stringify(MyDerived.myStatic) + "<br/>";
document.body.innerHTML += "<b>MyDerived2.myStatic:</b>&nbsp;" + JSON.stringify(MyDerived2.myStatic) + "<br/>";

结果如下：

MyDerived.myStatic: []
MyDerived2.myStatic: ["one","two","three"]

编辑：添加说明TypeScript和ECMA脚本6之间不同行为的示例。注意：ECMA脚本不支持静态属性，因此这些示例使用静态方法。

TypeScript代码：

class MyBase {
  static myStatic() { return []; }
}

class MyDerived extends MyBase {}

MyBase.myStatic = () => { return ['one', 'two', 'three']; }

class MyDerived2 extends MyBase {}

document.body.innerHTML += "<b>MyDerived.myStatic:</b>&nbsp;" + JSON.stringify(MyDerived.myStatic()) + "<br/>";
document.body.innerHTML += "<b>MyDerived2.myStatic:</b>&nbsp;" + JSON.stringify(MyDerived2.myStatic()) + "<br/>";

TypeScript结果：

MyDerived.myStatic: []
MyDerived2.myStatic: ["one","two","three"]

ECMA Script 6代码：ES6 Fiddle

class MyBase {
  static myStatic() { return []; }
}

class MyDerived extends MyBase {}

MyBase.myStatic = () => { return ['one', 'two', 'three']; };

class MyDerived2 extends MyBase {}

console.log("MyDerived.myStatic: " + JSON.stringify(MyDerived.myStatic()));
console.log("MyDerived2.myStatic: " + JSON.stringify(MyDerived2.myStatic()));

ECMA Script 6结果

MyDerived.myStatic: ["one","two","three"]
MyDerived2.myStatic: ["one","two","three"]

Answer 1

我是否正在观察TypeScript的预期行为？我是否正在观察ECMA Script 6的预期行为？

是的，是的。类允许运行时修改并按定义顺序处理。 inherit仅在定义点开始，因此取决于该点的基本属性。

Answer 2

See related TypeScript bug report

以下是TypeScript和ES6代码示例，它们具有一致的行为并遍历继承层次结构：

TypeScript代码：

class MyBase {
  static myStatic() { return []; }
}

class MyDerived extends MyBase {
  static myStatic() { return ['mickey', 'goofy', super.myStatic()]; }
}

MyBase.myStatic = () => { return ['one', 'two', 'three']; };

class MyDerived2 extends MyBase {
  static myStatic() { return ['mickey', 'goofy', super.myStatic()]; }
}

document.body.innerHTML += ("MyDerived.myStatic: " + JSON.stringify(MyDerived.myStatic()) + "<br/>");
document.body.innerHTML += ("MyDerived2.myStatic: " + JSON.stringify(MyDerived2.myStatic()) + "<br/>");

TypeScript结果：

MyDerived.myStatic: ["mickey","goofy",["one","two","three"]]
MyDerived2.myStatic: ["mickey","goofy",["one","two","three"]]

ES6代码：ES6 Fiddle

class MyBase {
  static myStatic() { return []; }
}

class MyDerived extends MyBase {
  static myStatic() { return ['mickey', 'goofy', super.myStatic()]; }
}

MyBase.myStatic = () => { return ['one', 'two', 'three']; };

class MyDerived2 extends MyBase {
  static myStatic() { return ['mickey', 'goofy', super.myStatic()]; }
}

console.log("MyDerived.myStatic: " + JSON.stringify(MyDerived.myStatic()));
console.log("MyDerived2.myStatic: " + JSON.stringify(MyDerived2.myStatic()));

ES6结果

MyDerived.myStatic: ["mickey","goofy",["one","two","three"]]
MyDerived2.myStatic: ["mickey","goofy",["one","two","three"]]

TypeScript类：静态和继承

2 个答案: