Tutorial examples of javascript cookie manipulation

cookie

Cookies, sometimes also used in their plural form Cookies, refer to the data (usually encrypted) stored on the user's local terminal by some websites in order to identify the user's identity and perform session tracking. The specifications defined in RFC2109 and 2965 are both obsolete, and the latest replaced specification is RFC6265.

The role of cookies

The server can use the arbitrariness of the information contained in Cookies to filter and regularly maintain this information to determine the status in HTTP transmission. The most typical application of cookies is to determine whether a registered user has logged in to the website. The user may be prompted whether to retain user information the next time he enters the website to simplify the login procedure. These are the functions of cookies. Another important application is "shopping cart" processing. Users may choose different products on different pages of the same website within a period of time, and this information will be written to Cookies so that the information can be retrieved when making the final payment.

jsSet cookie

document.cookie="popped=yes"

jsGet cookie

##function get_cookie (Name) { var search = Name + "="//Query retrieved value var returnvalue = "";//Return value if (document.cookie.length > 0) { sd = document.cookie.indexOf(search); if (sd!= -1) { sd += search.length; End = document.cookie.indexOf(";", sd); if (end == -1) End = document.cookie.length;

// Unescape () function can decode the string encoded by Escape (). Returnvalue=unescape(document.cookie.substring(sd, end)) } } return returnvalue; }
//Usage:
get_cookie("popped");

Set the expiration date for the cookie

For example: If you want to The cookie is set to expire after 10 days. This can be achieved like this:

//Get the current time var date=new Date();var expiresDays=10;//Set the date to 10 days later The time date.setTime(date.getTime()+expiresDays*24*3600*1000);//Set the two cookies userId and userName to expire after 10 days document.cookie="userId=828; userName=hulk; expires= "+date.toGMTString();

where GMT_String is a time string expressed in GMT format. This statement sets the userId cookie to GMT_String. Expiration time, after this time, the cookie will disappear and become inaccessible.

Delete cookie

In order to delete a cookie, you can set its expiration time to a past time, for example:

//Get the current time var date=new Date(); //Set date to the past time date.setTime(date.getTime()-10000); //Delete the userId cookie document.cookie="userId=828; expires="+date.toGMTString();

The above method is encapsulated below

var cookie = { set:function(key,val,time){//Set cookie method var date=new Date(); //Get the current time var expiresDays=time; //Set date to a time n days later Date.setTime(date.getTime()+expiresDays*24*3600*1000); //Format to the time recognized by the cookie Document.cookie=key + "=" + val +";expires="+date.toGMTString(); //Set cookie }, Get:function(key){//Get cookie method /*Get cookie parameters*/ var getCookie = document.cookie.replace(/[ ]/g,""); //Get the cookie and format the cookie to remove the space characters var arrCookie = getCookie.split(";") //The obtained cookie will be identified by "semicolon" and save the cookie to the array of arrCookie var tips; //Declare variable tips for(var i=0;i delete:function(key){ //Delete cookie method
var date = new Date(); //Get the current time
date.setTime(date.getTime()-10000); / /Set the date to the past time
DOCUMENT.COOKIE = key + "= v; expires =" + date.togmtring (); // Set cookie
} Return tips; } }

##Usage:

cookie.set("uesr","sss",24);//Set to expire in 24 days

alert(cookie .get("uesr"));//Get cookie

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