前端面试题:实现批量请求数据,并控制请求并发数量,最后所有请求结束之后,执行callback回调函数
constallRequest=["https://dog-facts-api.herokuapp.com/api/v1/resources/dogs?index=1","https://dog-facts-api.herokuapp.com/api/v1/resources/dogs?index=2","https://dog-facts-api.herokuapp.com/api/v1/res