实现一个日期公布讯息wel.innerHTML = `今天是${year}年的第<span style="color:r

function generateAndInsertContent(){
    let wel = document.getElementById("welcome")
    let date = new Date()
    let dateCur = date.valueOf() //当前的时间戳
    let date_ = new Date("2023-1-1")
    let datePre = date_.valueOf() //20230101的时间戳
    let day = Math.round((dateCur - datePre)/(1000*24*60*60)) //四舍五入获取天数
    let str = day>180? "下":"上"
    wel.innerHTML = `今天是${year}年的第<span style="color:red">${day}</span>天,你好,${str}半年！`
}
generateAndInsertContent()