Three common methods for HTML pages to automatically jump after 3 seconds

<span style="font-size:18px;"> </span><span style="font-size:24px;"><meta http-equiv="refresh" content="3;URL=res.html"> </span>
<span style="font-size:24px;">//Automatically jump to res.html after 3 seconds. The two belong to the same file. If you need to jump to the jsp page, you need to fill in the url address in the url (the data written in the address bar of the browser, such as: http://localhost:8080/TestDemo/1.jsp)</span>

window.setTimeout("alert('Hello, world')", 1000);

<script type="text/javascript">
onload=function(){ <span style="white-space:pre"> </span>//Load this method when entering the web page
setTimeout(go, 3000); <span style="white-space:pre"> </span> /*The unit in js is ms*/
};
function go(){
location.href="http://localhost:8080/TestDemo/index.jsp";
}
</script>
//Automatically execute the go method after 3 seconds and jump directly to the index.jsp page

<script type="text/javascript">
onload = function() {
setInterval(go, 1000);
};
var x=3; //Using global variables to execute
function go(){
x--;
if(x>0){
document.getElementById("sp").innerHTML=x; //The value of x is different each time.
}else{
location.href='res.html';
}
}
</script>