Cookies are a way for clients to store data and can be used to maintain state.
1. Set cookies:
a. No expiration time: (If the expiration time is not set, the default is a session-level cookie, and the browser will be closed if it is invalid)
The code copy is as follows:
function setCookie(name,value) {
document.cookie = name + '=' + escape(value);
}
b. Fixed expiration time:
The code copy is as follows:
function setCookie(name,value)
{
var Days = 30;
var exp = new Date();
exp.setTime(exp.getTime() + Days*24*60*60*1000);
document.cookie = name + "="+ escape (value) + ";expires=" + exp.toGMTString();
}
c. Custom expiration time:
The code copy is as follows:
//Set custom expiration time cookies
function setCookie(name,value,time)
{
var msec = getMsec(time); //Get milliseconds
var exp = new Date();
exp.setTime(exp.getTime() + msec*1);
document.cookie = name + "="+ escape (value) + ";expires=" + exp.toGMTString();
}
//Convert string time to milliseconds, 1 second = 1000 milliseconds
function getMsec(DateStr)
{
var timeNum=str.substring(0,str.length-1)*1; //Time quantity
var timeStr=str.substring(str.length-1,str.length); //The prefix of time unit, such as h represents hour
if (timeStr=="s") //20s means 20 seconds
{
return timeNum*1000;
}
else if (timeStr=="h") //12h means 12 hours
{
return timeNum*60*60*1000;
}
else if (timeStr=="d")
{
return timeNum*24*60*60*1000; //30d means 30 days
}
}
2. Read cookies:
The code copy is as follows:
function getCookie(name)
{
var arr,reg=new RegExp("(^| )"+name+"=([^;]*)(;|$)"); //Regular match
if(arr=document.cookie.match(reg)){
return unescape(arr[2]);
}
else{
return null;
}
}
3. Delete Cookies:
The code copy is as follows:
function delCookie(name)
{
var exp = new Date();
exp.setTime(exp.getTime() - 1);
var cval=getCookie(name);
if(cval!=null){
document.cookie= name + "="+cval+";expires="+exp.toGMTString();
}
}
4. Call example:
The code copy is as follows:
setCookie("name","hayden");
alert(getCookie("name"));
The above is all about JavaScript operation cookies in this article. I hope it will be helpful to everyone to learn JavaScript.