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I saw a typescript code like 

type Point = PartialPointX & { y: number; };

and I know '&' in javascript is "and",'|' is "OR", do they work different in typescript?

Haem
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cao champ
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1 Answers1

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That is an intersection type. Basically it combines multiple types into one so your new type Point is an object with the properties of PartialPointX and { y: number; }.

Murat Karagöz
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  • I know this,I don't understand why is "&" work different from js. – cao champ Aug 28 '19 at 08:38
  • @caochamp Because this is Typescript. – Murat Karagöz Aug 28 '19 at 08:49
  • When used on types (like in your question), they are the intersection ('&') and union ('|') operators. See https://stackoverflow.com/questions/33875609/typescript-operator answer for more details. When used on numbers, in Typescript and Javascript, they are bitwise operators (for AND and OR operations). See https://www.w3schools.com/js/js_bitwise.asp. – Rauks Aug 29 '19 at 13:05