typescript :将必需的属性转换为可选的

Question

如何将非可选属性转换为可选属性？这是代码:

interface Foo {
  bar: any // no '?', hence this prop is required
}

type KeysOfFoo = {
  [K in keyof Foo]: any
}

const keysOfFoo: KeysOfFoo = {} // No tsc error wanted here, got: "type '{}' is not assignable to type KeysOfFoo"

Answer 1

这里只是一个变化，虽然它不适用于问题中的问题。这里的解决方案也保留了键的类型。在这里阅读更多:https://www.typescriptlang.org/docs/handbook/advanced-types.html#index-types

interface Foo {
  bar: any // no '?', hence this prop is required
}

type KeysOfFoo = {
  [K in keyof Foo]?: Foo[K] // so that it retains the types
}