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In line 60359 of this type definition file, there is the following statement:
type ActivatedEventHandler = ( ev: Windows.ApplicationModel.Activation.IActivatedEventArgs & WinRTEvent ) => void;
In this context, what does the & symbol mean?
&
example:
type dog = {age: number, woof: Function}; type cat = {age: number, meow: Function}; // 类型weird是cat和dog的交集 // 它需要具有它们的所有属性的组合 type weird = dog & cat; const weirdAnimal: weird = {age: 2, woof: () => {'woof'}, meow: () => {'meow'}} interface extaprop { color: string } type catDog = weird & extaprop; // 类型现在还添加了color属性 const weirdAnimal2: catDog = {age: 2, woof: () => {'woof'}, meow: () => {'meow'}, color: 'red'} // 这与联合类型不同 // 下面的类型表示猫或狗 type dogOrCat = dog | cat;
&represents theintersectiontype in the type position.
https://www.typescriptlang.org/docs/handbook/2/objects.html#intersection-types
Quoted from the above document:
interface ErrorHandling { success: boolean; error?: { message: string }; } interface ArtworksData { artworks: { title: string }[]; } interface ArtistsData { artists: { name: string }[]; } // 这些接口被组合在一起，以具有 // 一致的错误处理和它们自己的数据。 type ArtworksResponse = ArtworksData & ErrorHandling; type ArtistsResponse = ArtistsData & ErrorHandling; const handleArtistsResponse = (response: ArtistsResponse) => { if (response.error) { console.error(response.error.message); return; } console.log(response.artists); };
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Intersection types in Typescript
example:
type dog = {age: number, woof: Function}; type cat = {age: number, meow: Function}; // 类型weird是cat和dog的交集 // 它需要具有它们的所有属性的组合 type weird = dog & cat; const weirdAnimal: weird = {age: 2, woof: () => {'woof'}, meow: () => {'meow'}} interface extaprop { color: string } type catDog = weird & extaprop; // 类型现在还添加了color属性 const weirdAnimal2: catDog = {age: 2, woof: () => {'woof'}, meow: () => {'meow'}, color: 'red'} // 这与联合类型不同 // 下面的类型表示猫或狗 type dogOrCat = dog | cat;&represents theintersectiontype in the type position.More TypeScript documentation on intersection types:
https://www.typescriptlang.org/docs/handbook/2/objects.html#intersection-types
Quoted from the above document:
interface ErrorHandling { success: boolean; error?: { message: string }; } interface ArtworksData { artworks: { title: string }[]; } interface ArtistsData { artists: { name: string }[]; } // 这些接口被组合在一起，以具有 // 一致的错误处理和它们自己的数据。 type ArtworksResponse = ArtworksData & ErrorHandling; type ArtistsResponse = ArtistsData & ErrorHandling; const handleArtistsResponse = (response: ArtistsResponse) => { if (response.error) { console.error(response.error.message); return; } console.log(response.artists); };