00030-hard-classpublickeys

[yunliuyan]

ClassPublicKeys

by jiangshan @jiangshanmeta

Implement the generic ClassPublicKeys<T> which returns all public keys of a class.

For example:

class A {
  public str: string
  protected num: number
  private bool: boolean
  getNum() {
    return Math.random()
  }
}

type publicKyes = ClassPublicKeys<A> // 'str' | 'getNum'

[yunliuyan]

完结

这个是给大伙开心的，hhh

代码实现

type ClassPublicKeys<T> = keyof T

[Naparte]

// 实现一个通用Last<T>，它接受一个数组T并返回其最后一个元素的类型。
type ClassPublicKeys<T> = keyof T;

class A {
    public str: string
    protected num: number
    private bool: boolean
    getNum() {
        return Math.random()
    }
}

type publicKyes = ClassPublicKeys<A> // 'str' | 'getNum'

let a: publicKyes = 'bool'

[Janice-Fan]

type ClassPublicKeys<T> = keyof T;

type publicKyes = ClassPublicKeys<A> // 'str' | 'getNum'