Native js implements holiday time countdown function (code attached)
This article mainly shares the sample code for implementing the holiday time countdown function in native js. Friends who are interested can come and see it together.
Knowledge points
1. Implementation principle:
Use end time - current time = Time difference
The time difference will naturally decrease by 1 second every time the current time passes.
So the current time needs to be updated once every second to achieve the countdown effect
2. What needs to be paid attention to is the conversion between times and the processing of the obtained values
3. Methods used:
obj.getTime() //换算成毫秒 Math.floor() //把小数点向下舍入结果取一个整数 50%24 // 这是对数值求余的方法，意思是 假如有50个小时，一天24个小时 这个得出的结果就是 余数是2
There are detailed comments in the complete code for specific numerical calculation processing
Complete code
Note: The code comes with a code that displays the current time. The standard format and countdown days
<!DOCTYPE html>
<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>demo</title>
<style>
body,h1,h2,h3,h4,h5,h6,hr,p,blockquote,dl,dt,dd,ul,ol,li,pre,form,fieldset,legend,button,input,textarea,th,td{margin:0;padding:0;}
h1,h2,h3,h4,h5,h6{font-size:100%;}
address,cite,dfn,em,var{font-style:normal;}
code,kbd,pre,samp{font-family:courier new,courier,monospace;}
ul,ol{list-style:none;}
a{text-decoration:none;}
a:hover{text-decoration:none;}
sup{vertical-align:text-top;}
sub{vertical-align:text-bottom;}
legend{color:#000;}
fieldset,img{border:0;}
button,input,select,textarea{font-size:100%;}
table{border-collapse:collapse;border-spacing:0;}
.clear{clear: both;float: none;height: 0;overflow: hidden;}
</style>
</head>
<body>
<p id="time"></p>
<br/>
<p id="day"></p>
<br/>
<p id="tm"></p>
<script type="text/javascript">
//在页面加载完后立即执行多个函数完美方案。
function addloadEvent(func){
var oldonload=window.onload;
if(typeof window.onload !="function"){
window.onload=func;
}
else{
window.onload=function(){
if(oldonload){
oldonload();
}
func();
}
}
}
addloadEvent(showTime);
addloadEvent(day);
addloadEvent(tb);
//在页面加载完后立即执行多个函数完美方案over。
//天时秒分倒计时
function tb(){
var myDate=new Date();//获取当前时间
var endtime=new Date("2018,1,1");//获取结束时间
//换算成秒 小数点向下舍入取整
var ltime=Math.floor((endtime.getTime()-myDate.getTime())/1000);
//console.log(ltime)
//换算成天 小数点向下舍入取整
var d=Math.floor(ltime/(24*60*60));
//换算成小时取去掉天数的余数（也就是小时） 小数点向下舍入取整
var h=Math.floor(ltime/(60*60)%24);
//换算成分钟取去掉小时的余数（也就是分钟） 小数点向下舍入取整
var m=Math.floor(ltime/60%60);
//换算成分钟取去掉分钟的余数（也就是秒） 小数点向下舍入取整
var s=Math.floor(ltime%60);
document.getElementById("tm").innerHTML="距2018年元旦还有:"+d+"天"+h+"小时"+m+"分钟"+s+"秒";
if(ltime<=0){
document.getElementById("tm").innerHTML="元旦快乐！";
clearTimeout(tb);
}
setTimeout(tb,1000);
}
//当秒数为个位数时前面+字符串0
function checkTime(i){
return i<10? "0"+i:""+i;
}
//当前时间标准格式
function showTime(){
var myDate=new Date();//获取当前时间
var year=myDate.getFullYear();//获取年份
var month=myDate.getMonth()+1;//获取月份是0-11的数字所以+1
var date=myDate.getDate();//日
var day=myDate.getDay();//
var h=myDate.getHours();//小时
var m=myDate.getMinutes();//分钟
var s=myDate.getSeconds();//秒
checkTime(m);
checkTime(s);
//console.log(day)
var week="日一二三四五六".charAt(day);
document.getElementById("time").innerHTML=year+"年"+month+"月"+date+"日"+"星期"+week+h+":"+m+":"+s;
setTimeout(showTime,1000);
}
//倒计时天数计算
function day(){
var myDate=new Date();//获取当前时间
var endtime=new Date("2018,1,1");//获取结束时间
//先换算成毫秒再相减就是时间差，再除以一天的毫秒数结果是带有小数点的，用math方法进一位取整
var ltime=Math.ceil((endtime.getTime()-myDate.getTime())/(24*60*60*1000));
document.getElementById("day").innerHTML="距2018年元旦还有:"+ltime+"天";
}
</script>
</body>
</html>are what I compiled for everyone. I hope it will be helpful to everyone in the future.
Related articles:
Detailed explanation of the use of event delegation in JS
Yuansheng JS creates a lottery page
p5.jsRealizing Golden Spiral Animation
The above is the detailed content of Native js implements holiday time countdown function (code attached). For more information, please follow other related articles on the PHP Chinese website!
From Websites to Apps: The Diverse Applications of JavaScriptApr 22, 2025 am 12:02 AMJavaScript is widely used in websites, mobile applications, desktop applications and server-side programming. 1) In website development, JavaScript operates DOM together with HTML and CSS to achieve dynamic effects and supports frameworks such as jQuery and React. 2) Through ReactNative and Ionic, JavaScript is used to develop cross-platform mobile applications. 3) The Electron framework enables JavaScript to build desktop applications. 4) Node.js allows JavaScript to run on the server side and supports high concurrent requests.
Python vs. JavaScript: Use Cases and Applications ComparedApr 21, 2025 am 12:01 AMPython is more suitable for data science and automation, while JavaScript is more suitable for front-end and full-stack development. 1. Python performs well in data science and machine learning, using libraries such as NumPy and Pandas for data processing and modeling. 2. Python is concise and efficient in automation and scripting. 3. JavaScript is indispensable in front-end development and is used to build dynamic web pages and single-page applications. 4. JavaScript plays a role in back-end development through Node.js and supports full-stack development.
The Role of C/C in JavaScript Interpreters and CompilersApr 20, 2025 am 12:01 AMC and C play a vital role in the JavaScript engine, mainly used to implement interpreters and JIT compilers. 1) C is used to parse JavaScript source code and generate an abstract syntax tree. 2) C is responsible for generating and executing bytecode. 3) C implements the JIT compiler, optimizes and compiles hot-spot code at runtime, and significantly improves the execution efficiency of JavaScript.
JavaScript in Action: Real-World Examples and ProjectsApr 19, 2025 am 12:13 AMJavaScript's application in the real world includes front-end and back-end development. 1) Display front-end applications by building a TODO list application, involving DOM operations and event processing. 2) Build RESTfulAPI through Node.js and Express to demonstrate back-end applications.
JavaScript and the Web: Core Functionality and Use CasesApr 18, 2025 am 12:19 AMThe main uses of JavaScript in web development include client interaction, form verification and asynchronous communication. 1) Dynamic content update and user interaction through DOM operations; 2) Client verification is carried out before the user submits data to improve the user experience; 3) Refreshless communication with the server is achieved through AJAX technology.
Understanding the JavaScript Engine: Implementation DetailsApr 17, 2025 am 12:05 AMUnderstanding how JavaScript engine works internally is important to developers because it helps write more efficient code and understand performance bottlenecks and optimization strategies. 1) The engine's workflow includes three stages: parsing, compiling and execution; 2) During the execution process, the engine will perform dynamic optimization, such as inline cache and hidden classes; 3) Best practices include avoiding global variables, optimizing loops, using const and lets, and avoiding excessive use of closures.
Python vs. JavaScript: The Learning Curve and Ease of UseApr 16, 2025 am 12:12 AMPython is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.
Python vs. JavaScript: Community, Libraries, and ResourcesApr 15, 2025 am 12:16 AMPython and JavaScript have their own advantages and disadvantages in terms of community, libraries and resources. 1) The Python community is friendly and suitable for beginners, but the front-end development resources are not as rich as JavaScript. 2) Python is powerful in data science and machine learning libraries, while JavaScript is better in front-end development libraries and frameworks. 3) Both have rich learning resources, but Python is suitable for starting with official documents, while JavaScript is better with MDNWebDocs. The choice should be based on project needs and personal interests.
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Atom editor mac version download
The most popular open source editor
SublimeText3 English version
Recommended: Win version, supports code prompts!
mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),
DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software
MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.
