<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>点击按钮显示时间</title>
<script>
function displayTime(){
fnDate(); //如果不先执行一次fnDate(),点击按钮之后会等一秒才显示时间
setInterval(function() {
fnDate();
},1000)
}
function fnDate() {
var oPara = document.getElementById("demo");
var date = new Date();
var year = date.getFullYear();
var month = date.getMonth();
var day = date.getDate();
var hour = date.getHours();
var minute = date.getMinutes();
var second = date.getSeconds();
var time = year+ "-"+ fnW(month+1) + "-"+ fnW(day)+ " "+ fnW(hour)+ ":"+ fnW(minute)+ ":"+ fnW(second)
oPara.innerHTML = time;
}
function fnW(str) {
var num ;
str >= 10? num = str: num = "0" +str ;
return num;
}
</script>
</head>
<body>
<div>
<p id="demo">这里显示时间</p>
<button type="button" onclick="displayTime()">点我看时间</button>
</div>
</body>
</html>
如果想打开页面就直接显示时间,要用window.onload
window.onload = function() {
setInterval(function () {
fnDate();
}, 1000);
Tip:getDay获取的是哪日,getDate获取的是星期几