同时K需要满足约束keyof T (keyof T 代表object中所有key组成的联合类型)// 自然,我们在函数内部访问obj[key]就不会提示错误了functiongetValueFromKey<Textendsobject,KextendskeyofT>(obj:T,key:K){returnobj[key];}
keyof T> > // 从T中排除存在于U中的key和类型 type Diff<T extends object, U extends object> = Pick< T, Exclude<keyof T, keyof U> >; type Overwrite< T extends object, U extends object, I = Diff<T, U> &
function get<T, K extends keyof T>(obj:T, key: K) { return obj[key] } console.log(get(obj, "name")) keyof还可以用于类型别名进行约束: interface Data { name: string age: number sex: string } type Options<T extends object> = { readonly [Key in keyof T]?:T[Key] } type B =...
function objectKeys<T extends object>(obj: T) { return Object.keys(obj) as Array<keyof T> } 3.pr中的应用 可以考虑在utils中进行函数导出。 export function objectEntries<T extends object>(obj: T) { return Object.entries(obj) as Array<[keyof T, T[keyof T]]> } export function objectKey...
typeRecord<Kextendskeyofany,T>= { [PinK]:T; }; keyof any: 等同于 string | number | symbol ,也就是说 K 只能是这三种类型 P in K: 指循环 K 类型 typeTKeys= 'A'| 'B'| 'C' interfaceIPeople{ name:string, age?: number,
functionupdateObjectProperties<Textendsobject,Uextendsobject>(target:T,source:U):void{for(constkeyinsource){if(source.hasOwnProperty(key)&&target.hasOwnProperty(key)){target[key]=source[key];}}}// 更新对象 `a` 的属性updateObjectProperties(a,b);console.log(a);// 输出结果: { name: 'Alice...
ObjectIds can be mapped asmongodb.ObjectId (Configurable with theuseMongoObjectIdparameter.) Auto-Batching / N+1 Prevention (Note: this is currently only supported by the Twirp clients.) If you're using ts-proto's clients to call backend micro-services, similar to the N+1 problem in SQL...
TconstcreateCustomObject=<TextendsObjectWithPropType<any>>(prop:any):T=>({prop});type Custom...
type OnlyObject<T extends any> = T extends Record<string, any> ? T : never; type types2_needed = OnlyObject<types2>;// type types2_needed = { a: { b: number; } } 把第二层的key拿出来 type keys2 = keyof types2_needed;// type keys2 = a ...
const list: Set<Function> = new Set()const autorun = (cb: Function) => {if (cb) {list.add(cb)}}const observable = <T extends object>(params: T) => {return new Proxy(params, {set(target, key, value, receiver) {const result = Reflect.set(target, key, value, receiver)list.for...