Writing and reading cookies using JavaScript

A cookie is the data stored on the user's local computer through a web browser. When the user accesses the web page again, the browser sends the data to the web page.

The most typical cookie is to determine whether a registered user has logged on to the website. The user may be prompted whether to keep the user information when entering the website for simplified login procedures, that is, "remember the password". These so-called memories are saved using cookies. Another important application scenario is "Shopping Cart processing". Users may choose different products on different pages of the same home within a period of time. The webpage writes the information to cookies, to extract information during payment.

In JS, we use the document. Cookie attribute to write and read cookies.

 

Cookie writing format: Document. Cookie = 'cookiename = '+ escape ('cookievalue') + '; expires =' + dataobj. togmtstring ()

View code

    Function  Writecookie (){
  VaR  Vdate  =    New  Date ();
Document. Cookie  =     "  Name =  "     +  Escape (  '  Write cookie  '  )  +     ' ; Expires =  '     +  Vdate. settime (vdate. gettime ()  +     1     *     24     *     60     *    60     *     1000  ). Togmtstring ();
}
  Function  Readcookie (){
  VaR  Cookievalue  =  Document. Cookie;
  VaR  Start  = Cookievalue. indexof (  '  Name =  '  );
  If  (Start  ! =     -  1  ){
Start  + =     '  Name  ' . Length  +     1  ;
  VaR  End  =  Cookievalue. indexof (  '  ;  '  , Start );
  If  (End  =     - 1  ){
Alert (Unescape (cookievalue. substring (start )));
}
  Else  {
Alert (Unescape (cookievalue. substring (START, end )));
}
}
}