<form action="">

        用户名：<input type="text" placeholder="请输入用户名">

        <button id="login">登录</button>

        <button id='demove'>删除</button>

    </form>

    <script type="module">

        //1.导入cookie模块

        import{ set,remove,get } from './cookie.js';

        // 2.获取事件

        const uernameTxt = document.querySelector('input');

        const login = document.getElementById('login');

        const demove = document.getElementById('demove');

        (function(){     

            //3.登录按钮注册点击事件     

            login.addEventListener('click',()=>{

                // 3.1如果value为空 什么都不干

                //不写的话 不为空 点击登录会创建一个空值cookie

                if( uernameTxt.value == '' ){                

                }else{

                    // 3.2否则 创建cookie 值为uernameTxt的value

                    set('uername',uernameTxt.value,{

                        //失效时间7天

                    maxAge: 7*24*3600                

                }); 

                }                                                                       

            },false); 

            // 4.删除按钮注册点击事件

            demove.addEventListener('click',()=>{

                // 4.1删除名为uername的cookie

                remove('uername');                                             

            },false);

            // 5.如果document.cookie存在则uernameTxt.value为uername的值

            //else否则为空 可以不写 默认为空

            if(document.cookie){

                uernameTxt.value = get('uername')

            }else{

                uernameTxt.value = '' 

            };                     

        })();