如何在TypeScript中为对象动态分配属性？

不念不忘少年蓝@ 2023-03-04 06:59 27阅读 0赞

本文翻译自：[How do I dynamically assign properties to an object in TypeScript?][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：**

var obj = {};
    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][https_stackoom.com_question_RkGB_TypeScript]

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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。**

var s = {};
    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：**

var obj:any = {}
      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：**

interface IFoo{
        bar:string;
        baz:string;
        boo:string;     
    }
    
    // How I tend to intialize 
    var foo:IFoo = <any>{};
    
    foo.bar = "asdf";
    foo.baz = "boo";
    foo.boo = "boo";
    
    // the following is an error, 
    // so you haven't lost type safety
    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：**

interface IFoo{
        bar?:string;
        baz?:string;
        boo?:string;    
    }
    
    // Now your simple initialization works
    var foo:IFoo = {};

*[Try it online][]* **[在线尝试][Try it online]**

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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”：**

var extend = <any>myObject;
    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：**

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

[How do I dynamically assign properties to an object in TypeScript]: https://oldbug.net/q/RkGB/How-do-I-dynamically-assign-properties-to-an-object-in-TypeScript
[https_stackoom.com_question_RkGB_TypeScript]: https://stackoom.com/question/RkGB/%E5%A6%82%E4%BD%95%E5%9C%A8TypeScript%E4%B8%AD%E4%B8%BA%E5%AF%B9%E8%B1%A1%E5%8A%A8%E6%80%81%E5%88%86%E9%85%8D%E5%B1%9E%E6%80%A7
[Try it online]: http://www.typescriptlang.org/Playground/#src=interface%20IFoo%7B%0A%09bar?:string;%0A%09baz?:string;%0A%09boo?:string;%20%09%0A%7D%0A%0A//%20How%20I%20tend%20to%20intialize%20%0Avar%20foo:IFoo%20=%20%7B%7D;%0A