如何从对象中省略“删除”许多属性？

我有两种返回以下类型的方法Pick<T, K> and Omit<T, K>省略号在哪里type Omit<T, K extends keyof T> = Pick<T, Exclude<keyof T, K>>。在从对象中删除多个属性时，我遇到了一些麻烦。

我有一个方法pickOne从对象中选择一个属性，一种方法pickMany从一个对象中选取多个属性的方法，以及从对象中删除一个属性的方法 omitOne。我想要一个 OmitMany 方法来从对象中删除多个属性，但在修复该方法中的类型错误时遇到了困难。

实施方法：

export let pickOne = <T, K extends keyof T>(entity: T, props: K ): Pick<T, K> => {
    return { [props] : entity[props] } as Pick<T, K>
}

export let pickMany = <T, K extends keyof T>(entity: T, props: K[]) => {
   return props.reduce((s, prop) => (s[prop] = entity[prop], s) , {} as Pick<T, K>)
}

export let omitOne = <T, K extends keyof T>(entity: T, prop: K): Omit<T, K> => {
    const { [prop]: deleted, ...newState} = entity
    return newState
}

// And the OmitMany for so far I tried, the problem is with storing the entity
// in a temporary variable. This function only omits the last property in the
// the array. I would like an implementation simular to pickMany.
export let omitMany = <T, K extends keyof T>(entity: T, props: K[]): Omit<T, K> => {
    let result = entity as Omit<T, K>
    props.forEach(prop => {
        result = omitOne(entity, prop)
    })
    return result
}

我期望的输出omitMany({x: 1, y: 2, z: 3, r: 4}, ['x', 'y'])成为类型的对象{z: number, r: number}，但正确知道输出是类型的对象{x: number, z: number, r: number}

你的问题与打字稿关系不大。这些类型按照您的预期工作omitMany，唯一的问题是在运行时它不会删除您期望的所有属性，这是由于您调用omitOne on entity而不是之前的结果。不幸的是，这需要一些类型断言，但它会起作用：

type Omit<T, K> = Pick<T, Exclude<keyof T, K>>

let omitOne = <T, K extends keyof T>(entity: T, prop: K): Omit<T, K> => {
    const { [prop]: deleted, ...newState } = entity
    return newState
}

let omitMany = <T, K extends keyof T>(entity: T, props: K[]): Omit<T, K> => {
    let result = entity as Omit<T, K>
    props.forEach(prop => {
        result = omitOne(result, prop as unknown as keyof Omit<T, K>) as Omit<T, K>
    })
    return result
}

let o = omitMany({ x: 1, y: 2, z: 3, r: 4 }, ['x', 'y'])
console.log(o)

操场 https://typescript-play.js.org/#code/C4TwDgpgBA8gtgS2AHgCoBooGkB8UC8UACggMYDWamAogB6kA2ArgCYTLkQgD2AZlBmw4cAKBEMIwKN0TAYAO2iEq2KBFrAI8lgGconHv1Q4AFFuBIQALgGYwAJ25gbWAJQ34SFbgJ4A3iJQQVCk3PI6Un5QANoOTgC6NmwSmiyYAHSZigDuAMrAAIaaUAC+BGryFqCBwfaSTPbyUDn5RRAiJWIp0rIAsgXyIOXeahpauvpcfAKm5pY2gnFgOi7R8e6wst54+P41Qd11OkwMUoRzoFAFep4ogrj7UEs66bzc9tQFpAAWJku+UACwWBUCOJzOPSQCggJjBpzsjjAVz0THk5Hk3GyTWuk0Mmy89xwrmR+LumAewJKrkedWADSacOAHS6kmk5RkSH6gxMUVoNgAjJhrFAAEyYABeNgAzJh7DYACylTDRADktBVmBVIBV6xEoXC3Ak6QY3AA5iZuK4gA