How to Set, Read and Delete Cookie using JavaScript.

This tutorial helps and teaches you how to Set, Read and Delete Cookie using JavaScript.

What is a cookie?

A cookie is simply a variable that your website page can store on or retrieve from the user's computer.

The idea is that the next time the user arrives at your website page, the value of the cookie can be read by the website page, and then used for a desired purpose.

<script type="text/javascript">

// Function to set a Cookie function vpb_set_cookie(cookie_name, cookie_value, total_days_allowed)  

{     

    if (total_days_allowed != "")      

    {         

       var vpb_date = new Date();

          vpb_date.setTime(vpb_date.getTime() + (total_days_allowed*24*60*60*1000));

        var vpb_expires = ";  expires="+vpb_date.toGMTString();     

     }     

     else { var vpb_expires = ""; }                

document.cookie = cookie_name+"="+cookie_value+vpb_expires+";  path=/";

} 

// Function to read a Cookie 

function vpb_read_cookie(cookie_name)  { 

    var vpb_cookie_name = cookie_name + "=";     var split_cookie_name = document.cookie.split('; ');     

    for( var i = 0;  i < split_cookie_name.length;  i++ )      

    {

        var vpb_split_cookie_name = split_cookie_name[i];         

       while ( vpb_split_cookie_name.charAt(0)==' ' )         

        {             vpb_split_cookie_name = vpb_split_cookie_name.substring(1,vpb_split_cookie_name.length);             

             if ( vpb_split_cookie_name.indexOf(vpb_cookie_name) == 0 )        

return vpb_split_cookie_name.substring(vpb_cookie_name.length,vpb_split_cookie_name.length);         

              }     

          }     

          return null; 

} 

// Function to delete a Cookie 

function vpb_delete_cookie(cookie_name)  {     

    vpb_set_cookie(cookie_name, "", -1); 

} 

//This is how you should use the above function to set the cookie with 10 days to keep the cookie active before it expires. vpb_set_cookie('fullname','Victor Olu',10); 

//This is how you should use the above function to delete your cookie - The cookie will be deleted if you uncomment the below code. 

//vpb_delete_cookie('fullname'); 

//This is how you should use the above function to read or get your cookie after setting it. 

alert( vpb_read_cookie('fullname') ); 

</script>

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