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) ? "" : "; 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.