constmergeFunc=<T,U>(arg1:T,arg2:U):T&U=>{letres={}asT&U//这里使用了类型断言res=Object.assign(arg1,arg2)returnres;}mergeFunc({a:'a'},{b:'b'}).a Object.assign是将两个对象属性合并 联合类型 联合类型与交叉类型很有关联,但是使用上却完全不同。 偶尔你会遇到这种情况,一个代码库希望...
AI代码解释 interfaceAnimal{name:string;}interfaceDogextendsAnimal{breed:string;}interfaceCatextendsAnimal{color:string;}functionisDog(animal:Animal):animalisDog{return(animalasDog).breed!==undefined;}functionprocess(animal:Dog|Cat){if(isDog(animal)){console.log('This is a dog');}else{console.log...
typeReadonlyObject<T>={readonly[PinkeyofT]:T[P];};constobj:ReadonlyObject<{name:string;age:number}>={name:"Alice",age:20,};obj.name="Bob";// Error: Cannot assign to 'name' because it is a read-only property. 类型守卫 类型守卫是 TypeScript 中一种用于缩小类型范围的机制。通过使用类...
// 支持:classCallResult{publicsucceeded():boolean{ ... }publicerrorMessage():string{ ... } }letres: CallResult = some_api_function('hello','world');if(!res.succeeded()) {console.log('Call failed: '+ res.errorMessage()); } any类型在TypeScript中并不常见,只有大约1%的TypeScript代码库...
泛型泛型主要是为了解决类型复用的问题。可以说泛型给了你在使用 ts 类型检测的体验同时,又提供了很好的类型扩展性、可维护性。在使用泛型类型时,可以将泛...
off clean-up, along with arbitrary amounts of cleanup. ADisposableStackis an object that has several methods for keeping track ofDisposableobjects, and can be given functions for doing arbitrary clean-up work. We can also assign them tousingvariables because — get this —they’re also...
Object.assign能把source: U身上的可枚举属性浅拷贝到target: T上,因此返回值类型为T & U 交叉类型A & B既是A也是B,因此具有各个源类型的所有成员: interface A { a: string; } interface B { b: number } let x: A & B; // 都是合法的 ...
--禁止自我赋值--> "no-self-assign": 2, <!--禁用逗号操作符--> "no-self-compare": 2, <!--禁用逗号操作符--> "no-sequences": 2, <!--禁止抛出异常字面量--> "no-throw-literal": 2, <!--禁用一成不变的循环条件--> "no-unmodified-loop-condition": 2, <!--禁止不必要的 .call...
Object.assign– a function that exhibits most of the behavior of spreading objects – is already modeled using intersection types, and we’ve seen very little negative feedback around that. Given that intersections model the common cases, and that they’re relatively easy to reason about for bot...
'no-return-assign': 'warn', // 禁用不必要的 return await 'no-return-await': 'warn', // 禁止自我赋值 'no-self-assign': 'warn', // 禁止自身比较 'no-self-compare': 'warn', // 禁止不必要的 catch 子句 'no-useless-catch': 'warn', ...