本文实例为大家分享了js实现数字滚动展示的具体代码，供大家参考，具体内容如下
效果图
<!DOCTYPE html> <html lang="en"> <head> <Meta charset="UTF-8"> <title>Title</title> <style> #t,#tt{ border: #ccc thin solid; width: 250px; height: 60px; display: flex; justify-content: space-around; align-items: center; font-size: 20px; } .t-num{ height: 100%; overflow: hidden; /*background-color: #ccc;*/ width: 25px; line-height: 60px; text-align: center; } .t-num-s{ display: block; height: 100%; width: 100%; /*border: red thin solid;*/ } </style> </head> <body> <div id="t"> </div> <div id="tt"> </div> <!--结构示例--> <!--<div>--> <!--<div class="divClass"><span class="spanclass">1</span></div>--> <!--<div class="divClass"><span class="spanclass">2</span></div>--> <!--<div class="divClass"><span class="spanclass">3</span></div>--> <!--<div class="divClass"><span class="spanclass">4</span></div>--> <!--</div>--> </body> </html> <script src="index.js"></script> <script> let num = 12345.5 //配置项 p:滚动熟读，height:数字容器的高度，spanclass：数字容器的classname,divClasss: span容器的class // numchange.config({p: 5}).change('t',num) let t = numchange() t.change('t',num) setInterval(() => { num = Math.random() * 100 + parseFloat(num) num = num.toFixed(2) t.change('t',num) },3000) let num1 = 12345 let t1 = numchange() t1.change('tt',num1) setInterval(() => { num1 = parseInt(Math.random() * 100) + parseInt(num1) t1.change('tt',num1) },3000) </script>
js代码
let numchange = function (){
let point = '.'
// 数字容器高度
let height = 60
// 每次滚动距离/滚动速度
let p = 3
// 数字spanclass
let spanClass = 't-num-s'
// 数字divclass
let divClass = 't-num'
//
let cache = {}
function createDiv(id,num,len,paddingNum){
let str = ''
for (let i = 0; i < len; i++) {
str += `<div class="${divClass}" id="${id+i}"><span class="${spanClass}">${paddingNum === undefined?num[i]:paddingNum}</span></div>`
}
return str
}
function initZero(id,count){
document.getElementById(id).innerHTML = createDiv(id,null,count,0)
}
function refresh(oldNum,newNum,id){
let len = newNum.length - oldNum.length;
for (let i = 0; i < len; i++) {
oldNum.unshift('0')
}
document.getElementById(id).innerHTML = createDiv(id,oldNum,oldNum.length)
}
function refresh1(oldNum,id){
let len = oldNum.length - newNum.length;
for (let i = 0; i < len; i++) {
oldNum.shift()
}
document.getElementById(id).innerHTML = createDiv(id,oldNum.length)
}
function scrollNum(id,order){
let h = num * height
let e = document.getElementById(id)
let t = setInterval(() => {
let m = e.scrollTop;
m = m + p
if(m > h){
clearInterval(t)
let cs = e.children
for (let i = cs.length-2; i >= 0; i--) {
e.removeChild(cs[i])
}
return
}
e.scrollTop = m
},10)
}
function createSpan(num){
let span = document.createElement('span')
span.className = spanClass
span.innerText = num
return span
}
function appendNum(id,start,end){
let f = document.createDocumentFragment()
let count = 0
if(start === end && isNaN(start)){
return 0
}
if(isNaN(start) && !isNaN(end)){
for (let i = 0; i <= end; i++) {
f.appendChild(createSpan(i))
count++
}
document.getElementById(id).appendChild(f)
return count
}
if(!isNaN(start) && isNaN(end)){
for (let i = start+1; i <= 9; i++) {
f.appendChild(createSpan(i))
count++
}
f.appendChild(createSpan('.'))
count++
document.getElementById(id).appendChild(f)
return count
}
if(start < end){
for (let i = start+1; i <= end; i++) {
f.appendChild(createSpan(i))
count++
}
}else if(start > end){
for (let i = start+1; i <= 9; i++) {
f.appendChild(createSpan(i))
count++
}
for (let i = 0; i <= end; i++) {
f.appendChild(createSpan(i))
count++
}
}else{
return 0
}
document.getElementById(id).appendChild(f)
return count
}
/**
* @param id 容器id
* @param num 展示的数字
*/
function change(id,num){
console.log(num)
let strArr = num.toString().split('');
let oldNum = cache[id]
// 如果没有缓存，开始数字全部填充0
if(!oldNum){
initZero(id,strArr.length)
oldNum = []
}else{
oldNum = cache[id].toString().split('')
// 如果新数字长，原来数字左侧填充0
if(oldNum.length < strArr.length){
refresh(oldNum,strArr,id)
// 如果新数字短，原来数字左侧移除
}else if(oldNum.length > strArr.length){
refresh1(oldNum,id)
}
}
// 循环比较每个数字差异，添加需要滚动的数字列
for (let i = 0,len = strArr.length; i < len; i++) {
let start = oldNum[i] !== point ? parseInt(oldNum[i]||0) : oldNum[i]
let end = strArr[i] !== point ? parseInt(strArr[i]||0) : strArr[i]
let count = appendNum(id+i,end)
if(count > 0){
// 数字滚动
scrollNum(id+i,i+1)
}
}
cache[id] = num
}
function config(param){
if(param.p){
p = param.p
}
if(param.height){
height = param.height
}
if(param.spanClass){
spanClass = param.spanClass
}
if(param.divClass){
divClass = param.divClass
}
return scroll
}
let scroll = {
change: change,config: config
}
return scroll
}
遗留问题：setInterval方法在切换页面后，会变快。解决方案1：用setTimeout代替setInterval。2.requestAnimFrame
