function call(fn,obj,...args){
    //判断
    if(obj === null || obj === undefined){
        obj = globalThis //全局对象 es11里的
    }
    //给obj赋予临时函数
    obj.temp = fn;
    //调用函数
    let result = obj.temp(...args)
    //销毁temp
    delete obj.temp
    //返回结果
    return result
}