如何在TypeScript中為對象動態分配屬性？

本文翻譯自：How do I dynamically assign properties to an object in TypeScript?

If I wanted to programatically assign a property to an object in Javascript, I would do it like this: 如果我想以編程方式將屬性分配給Javascript中的對象，則可以這樣做：

1.  
   var obj = {};
2.  
   obj.prop = "value";

But in TypeScript, this generates an error: 但是在TypeScript中，這會產生一個錯誤：

The property 'prop' does not exist on value of type '{}' 類型“ {}”的值不存在屬性“ prop”

How am I supposed to assign any new property to an object in TypeScript? 我應該如何在TypeScript中為對象分配任何新屬性？

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#1樓

參考：https://stackoom.com/question/RkGB/如何在TypeScript中為對象動態分配屬性

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#2樓

Although the compiler complains it should still output it as you require. 盡管編譯器抱怨它仍應按您的要求輸出。 However, this will work. 但是，這將起作用。

1.  
   var s = {};
2.  
   s[ 'prop'] = true;

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#3樓

您可以添加此聲明以使警告靜音。

declare var obj: any;

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#4樓

Or all in one go: 或一勞永逸：

1.  
   var obj:any = {}
2.  
   obj.prop = 5;

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#5樓

I tend to put any on the other side ie var foo:IFoo = <any>{}; 我傾向於把any放在另一邊，即var foo:IFoo = <any>{}; So something like this is still typesafe: 所以像這樣的東西仍然是類型安全的：

1.  
   interface IFoo{
2.  
   bar: string;
3.  
   baz: string;
4.  
   boo: string;
5.  
   }
6.  
    
7.  
   // How I tend to intialize
8.  
   var foo:IFoo = <any>{};
9.  
    
10.  
    foo.bar = "asdf";
11.  
    foo.baz = "boo";
12.  
    foo.boo = "boo";
13.  
     
14.  
    // the following is an error,
15.  
    // so you haven't lost type safety
16.  
    foo.bar = 123;

Alternatively you can mark these properties as optional: 另外，您可以將這些屬性標記為可選：

1.  
   interface IFoo{
2.  
   bar?:string;
3.  
   baz?:string;
4.  
   boo?:string;
5.  
   }
6.  
    
7.  
   // Now your simple initialization works
8.  
   var foo:IFoo = {};

Try it online 在線嘗試

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#6樓

Store any new property on any kind of object by typecasting it to 'any': 將任何新屬性存儲在任何類型的對象上，方法是將其類型轉換為“ any”：

1.  
   var extend = <any>myObject;
2.  
   extend.NewProperty = anotherObject;

Later on you can retrieve it by casting your extended object back to 'any': 稍后，您可以通過將擴展對象轉換回'any'來檢索它：

1.  
   var extendedObject = <any>myObject;
2.  
   var anotherObject = <AnotherObjectType>extendedObject.NewProperty;