JavaScript cookie Technology Detailed _javascript tips

Use JS to set cookies, read cookies, delete cookies
JavaScript is a script that runs on the client, so it is generally not possible to set a session because the session is run on the server side.

Cookies are run on the client, so you can use JS to set cookies.

Suppose there is a case in which, in a use-case process, from a page to the B page, if the a page using JS variable temp saved a variable of the value, in the B page, the same need to use JS to reference the TEMP variable value, for JS global variable or static variable life cycle is limited, When a page jump occurs or the page closes, the values of these variables are loaded back in, that is, the saved effect is not reached. The best solution to this problem is to use cookies to save the value of the variable, so how do you set and read cookies?
First you need to know a little bit about the structure of the cookie, simply put: The cookie is stored as a key-value pair, i.e., the key=value format. Each cookie is generally ";" Separated.

JS Set Cookies:

Assuming that the value of the variable username ("Jack") in the page A is stored in the cookie, the key value is name, the corresponding JS code is:
document.cookie= "Name=" +username;

JS Read cookies:
Suppose the content stored in the cookie is:name=jack;password=123

The JS code to get the value of the variable username in page B is as follows:

var username=document.cookie.split (";") 

[0].split ("=") [1];

JS Operation Cookie Method! 
  Write cookies 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 (); //Read cookies function GetCookie (name) {var arr,reg=new RegExp ("(^|)" +name+ "= ([^;]

  *)(;|$)"); 
  if (Arr=document.cookie.match (reg)) return unescape (arr[2]); 
else return null; 
  //Delete the cookie 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 (); 
//Use sample Setcookie ("name", "Hayden");

Alert (GetCookie ("name"));


If you need to set the custom expiration//Then replace the above Setcookie function with the following two functions on OK; 
  Program code function Setcookie (name,value,time) {var strsec = getsec (time); 
  var exp = new Date (); 
  Exp.settime (Exp.gettime () + strsec*1); Document.cookiE = name + "=" + Escape (value) + "; expires=" + exp.togmtstring (); 
  function Getsec (str) {alert (str); 
  var str1=str.substring (1,str.length) *1; 
  var str2=str.substring (0,1); 
  if (str2== "s") {return str1*1000; 
  else if (str2== "H") {return str1*60*60*1000; 
  else if (str2== "D") {return str1*24*60*60*1000; 

 } 
}

This is an example of a set expiration time: 
//S20 is for 20 seconds 
//h refers to the hour, such as 12 hours is: H12 
//d is the number of days, 30 days: D30 Setcookie

("name", "Hayden", " S20 ");

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