如何在TypeScript中为对象动态分配属性？

本文翻译自：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: 如果我想以编程方式将属性分配给Javascript中的对象，则可以这样做：

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

But in TypeScript, this generates an error: 但是在TypeScript中，这会产生一个错误：

The property 'prop' does not exist on value of type '{}' 类型“ {}”的值不存在属性“ prop”

How am I supposed to assign any new property to an object in TypeScript? 我应该如何在TypeScript中为对象分配任何新属性？

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#1楼

参考：https://stackoom.com/question/RkGB/如何在TypeScript中为对象动态分配属性

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#2楼

Although the compiler complains it should still output it as you require. 尽管编译器抱怨它仍应按您的要求输出。 However, this will work. 但是，这将起作用。

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

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#3楼

您可以添加此声明以使警告静音。

declare var obj: any;

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#4楼

Or all in one go: 或一劳永逸：

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

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#5楼

I tend to put any on the other side ie var foo:IFoo = <any>{}; 我倾向于把any放在另一边，即var foo:IFoo = <any>{}; So something like this is still typesafe: 所以像这样的东西仍然是类型安全的：

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

Alternatively you can mark these properties as optional: 另外，您可以将这些属性标记为可选：

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

Try it online 在线尝试

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#6楼

Store any new property on any kind of object by typecasting it to 'any': 将任何新属性存储在任何类型的对象上，方法是将其类型转换为“ any”：

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

Later on you can retrieve it by casting your extended object back to 'any': 稍后，您可以通过将扩展对象转换回'any'来检索它：

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