面试系列

三次握手四次挥手 客户端发起请求，携带请求序列号 服务端接收，发送应答，返回请求序列号，携带新的服务序列号 客户端收到应答和对应的请求序列号，发送...

html.spec.whatwg.org 对属性的描述 The async and defer attributes are boolean attributes that indicate how the script should be evaluated. Classic scripts may specify defer or async, but must not specify either unless the src attribute is present. Module scripts may specify the async attribute, but must not specify the defer attribute. Async 和defer 是用于指示脚本应...