题解 | #instanceof#

// Fn写成小写了 调试了半天   

const _instanceof = (target, Fn) => {

      let obj = {

        number: true,

        string: true,

        null: true

    }

    let result = typeof target

    if (obj[result]) return false

    let proto = target.__proto__

    let prototype = Fn.prototype

    while (proto) {

        if (proto === prototype) return true

        if (proto === null) return false

        proto = proto.__proto__

    }

}