实现一个函数clone about fedexercises HOT 1 OPEN

       let newobj
        let str

        if (typeof obj !== 'object') {
            return
        } else if (window.JSON) {
            str = JSON.stringify(obj)
            newobj = JSON.parse(str)
        } else {
            for (const i in obj) {
                if ({}.hasOwnProperty.call(obj, i)) {
                    newobj[i] = typeof obj[i] === 'object' ?
                    this.clone(obj[i]) : obj[i]
                }
            }
        }

        return newobj