如何在TypeScript中处理对象并添加新的字段？-灵析社区

一个方式就是问题中所展示的, 但是不太灵活, 可以使用接口的任意属性: interface Person { name: string; age?: number; [propName: string]: any; } let tom: Person = { name: 'Tom', gender: 'male' }; 使用 `[propName: string]` 定义了任意属性取 string 类型的值。 需要注意的是，**一旦定义了任意属性，那么确定属性和可选属性的类型都必须是它的类型的子集：** interface Person { name: string; age?: number; [propName: string]: string; } let tom: Person = { name: 'Tom', age: 25, gender: 'male' }; // index.ts(3,5): error TS2411: Property 'age' of type 'number' is not assignable to string index type 'string'. // index.ts(7,5): error TS2322: Type '{ [x: string]: string | number; name: string; age: number; gender: string; }' is not assignable to type 'Person'. // Index signatures are incompatible. // Type 'string | number' is not assignable to type 'string'. // Type 'number' is not assignable to type 'string'. > [http://ts.xcatliu.com/basics/type-of-object-> interfaces.html](https://link.segmentfault.com/?enc=HTiQkTqmYAJzzXtJJJvNVg%3D%3D.gC07qgJFXbaWfFwkKdIJh8DqIk9sFAL%2BXN3phdTBBOi5zzHaJ%2BR%2FwFFjOqujv%2F4i1tE9SQDRjOVZ6z2ioqVbJw%3D%3D)