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How JavaScript uses cookies to record temporary visitor information_javascript tips

WBOY
WBOYOriginal
2016-05-16 16:05:191249browse

The example in this article describes how JavaScript uses cookies to record temporary visitor information. Share it with everyone for your reference. The specific analysis is as follows:

When the user visits the webpage for the first time, the user will be prompted to enter a nickname and then write it into the cookie. When the user comes again, the cookie information will be read, the user's nickname will be extracted, and the user is welcome 

<!DOCTYPE html>
<html>
<head>
<script>
function getCookie(c_name)
{
var c_value = document.cookie;
var c_start = c_value.indexOf(" " + c_name + "=");
if (c_start == -1)
 {
 c_start = c_value.indexOf(c_name + "=");
 }
if (c_start == -1)
 {
 c_value = null;
 }
else
 {
 c_start = c_value.indexOf("=", c_start) + 1;
 var c_end = c_value.indexOf(";", c_start);
 if (c_end == -1)
  {
  c_end = c_value.length;
  }
 c_value = unescape(c_value.substring(c_start,c_end));
 }
return c_value;
}
function setCookie(c_name,value,exdays)
{
var exdate=new Date();
exdate.setDate(exdate.getDate() + exdays);
var c_value=escape(value) + ((exdays==null) &#63; "" : "; expires="+exdate.toUTCString());
document.cookie=c_name + "=" + c_value;
}
function checkCookie()
{
var username=getCookie("username");
if (username!=null && username!="")
 {
 alert("Welcome again " + username);
 }
else
 {
 username=prompt("Please enter your name:","");
 if (username!=null && username!="")
  {
  setCookie("username",username,365);
  }
 }
}
</script>
</head>
<body onload="checkCookie()">
</body>
</html>

I hope this article will be helpful to everyone’s JavaScript programming design.

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