js implements countdown function after sending verification code_javascript skills

I shared before that I can only use js to implement the countdown function. Later, when I tested it, I found that after refreshing or closing the web page, the countdown could no longer be used. I couldn’t find a suitable solution online, so I wrote one myself. This time It is an optimized version. It can still be used after refreshing or reopening the web page

Special instructions:

The validity time of the initial creation of the cookie is 60 seconds. In other words, if you close the webpage when the countdown is 20 and reopen it after 20 seconds, there will be no countdown displayed; however, if the countdown is 20 , close the page, and if you reopen the page within 20 seconds, a countdown will be displayed.

html code

<input id="second" type="button" value="免费获取验证码" />

JS operation on cookies

//发送验证码时添加cookie
function addCookie(name,value,expiresHours){ 
  var cookieString=name+"="+escape(value); 
  //判断是否设置过期时间,0代表关闭浏览器时失效
  if(expiresHours>0){ 
    var date=new Date(); 
    date.setTime(date.getTime()+expiresHours*1000); 
    cookieString=cookieString+";expires=" + date.toUTCString(); 
  } 
    document.cookie=cookieString; 
} 
//修改cookie的值
function editCookie(name,value,expiresHours){ 
  var cookieString=name+"="+escape(value); 
  if(expiresHours>0){ 
   var date=new Date(); 
   date.setTime(date.getTime()+expiresHours*1000); //单位是毫秒
   cookieString=cookieString+";expires=" + date.toGMTString(); 
  } 
   document.cookie=cookieString; 
} 
//根据名字获取cookie的值
function getCookieValue(name){ 
   var strCookie=document.cookie; 
   var arrCookie=strCookie.split("; "); 
   for(var i=0;i<arrCookie.length;i++){ 
    var arr=arrCookie[i].split("="); 
    if(arr[0]==name){
     return unescape(arr[1]);
     break;
    }else{
       return ""; 
       break;
     } 
   } 
    
}

Main logic code

$(function(){
  $("#second").click(function (){
    sendCode($("#second"));
  });
  v = getCookieValue("secondsremained");//获取cookie值
  if(v>0){
    settime($("#second"));//开始倒计时
  }
})
//发送验证码
function sendCode(obj){
  var phonenum = $("#phonenum").val();
  var result = isPhoneNum();
  if(result){
    doPostBack('${base}/login/getCode.htm',backFunc1,{"phonenum":phonenum});
    addCookie("secondsremained",60,60);//添加cookie记录,有效时间60s
    settime(obj);//开始倒计时
  }
}
//将手机利用ajax提交到后台的发短信接口
function doPostBack(url,backFunc,queryParam) {
  $.ajax({
    async : false,
    cache : false,
    type : 'POST',
    url : url,// 请求的action路径
    data:queryParam,
    error : function() {// 请求失败处理函数
    },
    success : backFunc
  });
}
function backFunc1(data){
  var d = $.parseJSON(data);
  if(!d.success){
    alert(d.msg);
  }else{//返回验证码
    alert("模拟验证码:"+d.msg);
    $("#code").val(d.msg);
  }
}
//开始倒计时
var countdown;
function settime(obj) { 
  countdown=getCookieValue("secondsremained");
  if (countdown == 0) { 
    obj.removeAttr("disabled");  
    obj.val("免费获取验证码"); 
    return;
  } else { 
    obj.attr("disabled", true); 
    obj.val("重新发送(" + countdown + ")"); 
    countdown--;
    editCookie("secondsremained",countdown,countdown+1);
  } 
  setTimeout(function() { settime(obj) },1000) //每1000毫秒执行一次
} 
//校验手机号是否合法
function isPhoneNum(){
  var phonenum = $("#phonenum").val();
  var myreg = /^(((13[0-9]{1})|(15[0-9]{1})|(18[0-9]{1}))+\d{8})$/; 
  if(!myreg.test(phonenum)){ 
    alert('请输入有效的手机号码！'); 
    return false; 
  }else{
    return true;
  }
}

The above is the entire content of this article, I hope you all like it.