JavaScript calls Cookies

Cookies

used to store information and interact with the server, so cookies can be used by the front- end Backend

It is worth mentioning that although the cookie is stored as a file on the client computer,

However, the browser will only allow the website that created the cookie to access its own cookies.

The following experiment takes the form as an example

User:<type= "text"  ID= "user"/><  /> Password: <  type= "password"  onblur= "set ()"  ID= "Pass"  /></>

The cookie is a property of the document object and supports write and read.

To create a cookie syntax format:

Document.cookie = "Name=value"

After the user has entered the account password, the value of the cookie is stored through the Blur event.

        function  set () {            // If the value of the form is not empty, then save its value if            (user.value! = "" &&pass.value!= "") {                document.cookie= "username =" + user.value;                Document.cookie= "Password =" +   pass.value;             }
        }

To view the value of a cookie that has already been stored on a webpage:

alert (document.cookie); The result is username=hello;password=123456

alert (typeof document.cookie); Result is a string

To obtain the cookie value for the cookie name:

functionGet_cookies_value (CNAME) {varCOO =Document.cookie; //the next line has a detail: if you do not add =, you cannot avoid the situation when the COO value is equal to the COO name.    varindex = coo.indexof (cname + "=")
    //if the name exists    if(Index!=-1){    //gets the start position of the value       varIndex_start = index + cname.length + 1;//equals sign occupies one bit       varIndex_end = Coo.indexof (";", Index_start); if(Index_end = =-1){       //If there is no semicolon, the value is the last, so the end index is the COO lengthIndex_end=coo.length; }       //intercept the value and return       varValue =coo.substring (index_start,index_end); returnvalue; }}

You can then insert the cookie value into the form when the page is loaded:

var user = document.getElementById ("user"); var pass = document.getElementById ("pass"); if (document.cookie!= "") {    User.value= Get_cookies_value ("user");     Pass.value= get_cookies_value ("pass");}

JavaScript calls Cookies