HTML文字展示按秒变化的动态时钟

 

  <h3 id="clock"></h3>

function clock() {
            let date = new Date()
            let year = date.getFullYear();
            let month = date.getMonth() + 1;
            let day = date.getDate();
            let hours = date.getHours();
            let minutes = date.getMinutes();
            let seconds = date.getSeconds();
            month = month < 10 ? '0' + month : month;
            day = day < 10 ? '0' + day : day;
            hours = hours < 10 ? '0' + hours : hours
            minutes = minutes < 10 ? '0' + minutes : minutes;
            seconds = seconds < 10 ? '0' + seconds : seconds;
            let time = year + '年' + month + '月' + day + '日 ' + hours + ':' + minutes + ':' + seconds;
            document.getElementById("clock").innerHTML = time
            setTimeout("clock()", 1000);
        }