localStorage 设置过期时间的方法实现

Storage.prototype.setExpire=(key,value,expire) =>{
 };
Storage.setExpire(key,value,expire);

Storage.prototype.setExpire=(key, value, expire) =>{
    let obj={
        data:value,
        time:Date.now(),
        expire:expire
    };
    localStorage.setItem(key,JSON.stringify(obj));
}

Storage.prototype.getExpire= key =>{
    let val =localStorage.getItem(key);
    if(!val){
        return val;
    }
    val =JSON.parse(val);
    if(Date.now()-val.time>val.expire){
        localStorage.removeItem(key);
        return null;
    }
    return val.data;
}

localStorage.setExpire("token",'xxxxxx',5000);
window.setInterval(()=>{
    console.log(localStorage.getExpire("token"));
},1000)