Argument of type '{ color: string; raidus: number; }' is not assignable to parameter of type 'Colorful & Circle'. Object literal may only specify known properties, but 'raidus' does not exist in type 'Colorful & Circle'. Did you mean to write 'radius'? */ 接口VS 交叉类型 目前,我们...
extendStatics = Object.setPrototypeOf || ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) || function (d, b) { for (var p in b) if (Object.prototype.hasOwnProperty.call(b, p)) d[p] = b[p]; }; return extendStatics(d, b); }; retu...
typeof类型保护用于确定变量的类型,它只能识别以下类型: boolean string bigint symbol undefined function number 对于这个列表之外的任何内容,typeof类型保护只会返回object。typeof类型保护可以写成以下两种方式: typeof v !== "typename" typeof v === "typename" typename只能是number、string、boolean和symbol四种...
`); home.resident.age++;} function evict(home: Home) { // But we can't write to the 'resident' property itself on a 'Home'. home.resident = { // Cannot assign to 'resident' because it is a read-only property. name: "Victor the Evictor", age: 42, };} TypeScri...
typeStatus='not_started'|'progress'|'completed'|'failed';constsetStatus=(status:Status)=>{db.object.setStatus(status); };setStatus('progress');setStatus('offline');// ❌ 类型“"offline"”的参数不能赋给类型“Status”的参数。 1.
__extends) || (function () { var extendStatics = function (d, b) { extendStatics = Object.setPrototypeOf || ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) || function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] ...
在“NodeJS系列(14)- TypeScript (一) | 安装 TypeScript、常用类型” 里,我们简单介绍了 TypeScript 的安装配置,讲解和演示了 TypeScript 常用类型。本文继续介绍 TypeScript 对象类型 (Object Types)。TypeScri
Object.setPrototypeOf(this, MsgError.prototype); } sayHello() { return "hello " + this.message; } }然而, MsgError 的任何子类也必须手动设置原型。对于不支持 Object.setPrototypeOf 的运行时, 你可以使用__proto__ 来代替。不幸的是,这些变通方法在IE10 和更早的版本上不起作用。我们可以手动将原型...
Now, TypeScript will not throw an error, and the occupation property will be removed as expected. The trick here is this part: (user as {occupation?: string}). This is a type assertion that tells the compiler to treat user as an object with an optional occupation property of type string...
push(true) //报错 TS2345: Argument of type 'boolean' is not assignable to parameter of type 'string | number'. Class 类 get 和 set 有点类似 Object.defineProperty 的数据劫持。 class Test { _value: any constructor(value: any) { this._value = value } get value(){ return this._...