為了加強對JavaScript原生代碼的編寫能力，以及鞏固setTimeout()的使用方法，制作了一個倒計時的demo，倒計時在現(xiàn)在的網(wǎng)站中算是一個常見的小功能，如果大家喜歡的話可以留下，就當作一個日常實用的小腳本。

實現(xiàn)思路

1、先獲取小時值 將小時值減1開始進行倒計時 分鐘59 秒數(shù)592、秒數(shù)的個位從9開始遞減，當秒數(shù)個位小于0時，秒數(shù)的十位減13、秒數(shù)的十位小于0時，分鐘的個位減14、分鐘的個位小于0時，分鐘的十位減15、分鐘的十位小于0時，小時減16、小時數(shù)小于0后停止計時全部為0

實現(xiàn)代碼

html

<p>倒計時：</p><span id='hour'>5</span><span>:</span><span id='minuteTen'>0</span><span id='minuteBit'>0</span><span>:</span><span id='secondTen'>0</span><span id='secondBit'>0</span>

css

span{ display: inline-block; width: 20px; height: 20px; background-color: #000000; color: #ffffff; text-align: center; }

JavaScript

function time(){ /*小時*/ var hourTxt = document.getElementById('hour'); var hour = parseInt(document.getElementById('hour').innerHTML); /*分鐘*/ var minuteTenTxt = document.getElementById('minuteTen'); var minuteBitTxt = document.getElementById('minuteBit'); var minuteTen = parseInt(document.getElementById('minuteTen').innerHTML); var minuteBit = parseInt(document.getElementById('minuteBit').innerHTML); /*秒*/ var secondTenTxt = document.getElementById('secondTen'); var secondBitTxt = document.getElementById('secondBit'); var secondTen = parseInt(document.getElementById('secondTen').innerHTML); var secondBit = parseInt(document.getElementById('secondBit').innerHTML); function start(){ hour--; hourTxt.innerHTML = hour; minuteTen = 5; minuteTenTxt.innerHTML = minuteTen; minuteBit = 9; minuteBitTxt.innerHTML = minuteBit; secondTen = 5; secondTenTxt.innerHTML = secondTen; secondBit = 9; secondBitTxt.innerHTML = secondBit; /*secondBit開始自減*/ function second(){ secondBit--; secondBitTxt.innerHTML = secondBit; /*十秒過后*/ if(secondBit < 0){ secondTen--; secondTenTxt.innerHTML = secondTen; secondBit = 9; secondBitTxt.innerHTML = secondBit; /*繼續(xù)倒計時*/ setTimeout(second,1000); /*一分鐘過后*/ if(secondTen < 0){ minuteBit--; minuteBitTxt.innerHTML = minuteBit; secondTen = 5; secondTenTxt.innerHTML = secondTen; secondBit = 9; secondBitTxt.innerHTML = secondBit; /*十分鐘過后*/ if(minuteBit < 0){ minuteTen--; minuteTenTxt.innerHTML = minuteTen; minuteBit = 9; minuteBitTxt.innerHTML = minuteBit; } /*一個小時過后*/ if(minuteTen < 0){ hour--; hourTxt.innerHTML = hour; minuteTen = 5; minuteTenTxt.innerHTML = minuteTen; minuteBit = 9; minuteBitTxt.innerHTML = minuteBit; secondTen = 5; secondTenTxt.innerHTML = secondTen; secondBit = 9; secondBitTxt.innerHTML = secondBit; } /*倒計時結(jié)束*/ if(hour < 0 ){ hour = 0; hourTxt.innerHTML = hour; minuteTen = 0; minuteTenTxt.innerHTML = minuteTen; minuteBit = 0; minuteBitTxt.innerHTML = minuteBit; secondTen = 0; secondTenTxt.innerHTML = secondTen; secondBit = 0; secondBitTxt.innerHTML = secondBit; clearTimeout(second); clearTimeout(start); } } }else{ setTimeout(second,1000); } } setTimeout(second,1000); } setTimeout(start,1000);}

執(zhí)行頁面

結(jié)束頁面

以上就是本文的全部內(nèi)容，希望對大家的學(xué)習(xí)有所幫助，也希望大家多多支持好吧啦網(wǎng)。