本文实例为大家分享了JS实现留言板增删功能的具体代码，供大家参考，具体内容如下
## **JS实现简易留言板的增删功能**
一个很简单的留言板，实现**增删**功能，因为没有数据库，所以只是一个静态的留言板功能。
**修改**功能其实也可以添加，但是我现在技术不够，等以后可能会添加**修改**功能。
代码很简单，注释很清楚。```
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<style type="text/css">
* {
margin: 0;
padding: 0;
list-style: none;
}
.cle:after {
height: 0;
clear: both;
visibility: hidden;
display: none;
content: "";
}
.bbslist {
width: 400px;
margin: 10px auto;
border-radius: 5px;
background: #A6A6A6;
border: 1px solid #a6a6a6;
}
.bbslist>ul {
margin: 8px 10px 10px 10px;
display: block;
clear: both;
text-align: center;
box-shadow: 3px 3px 25px #A6A6A6;
}
.bbslist>ul>li {
background: #f4f4f4;
margin: 10px 0;
line-height: 30px;
height: 30px;
border-radius: 5px;
text-align: center;
box-shadow: 3px 3px 17px #A6A6A6;
padding: 0 5px;
font-size: 12px;
border: 1px solid #a6a6a6;
position: relative;
transition: all 0.5s;
animation: liBg 0.3s;
overflow: hidden;
}
@keyframes liBg {
from {
background: #442222;
opacity: 0;
left: -20px;
height: 0;
}
to {
background: #f4f4f4;
opacity: 1;
left: 0;
height: 30px;
}
}
.mesDiv {
width: 400px;
background: #eee;
height: 130px;
border: 1px solid #a6a6a6;
margin: 20px auto;
border-radius: 5px;
box-shadow: 3px 3px 17px #A6A6A6;
animation: msgHeight 0.5s;
overflow: hidden;
}
@keyframes msgHeight {
from {
height: 0;
margin-top: 50px;
opacity: 0;
}
to {
height: 130px;
margin-top: 20px;
opacity: 1;
}
}
.inputSty {
width: 90%;
height: 30px;
display: block;
color: #666;
border: 1px solid #ddd;
padding-left: 5px;
line-height: 30px;
font-size: 12px;
clear: both;
margin: 10px auto;
border-radius: 5px;
}
.btnSty {
width: 30%;
height: 25px;
margin: 0 auto;
display: block;
cursor: pointer;
transition: all 0.2s;
border-radius: 5px;
box-shadow: 3px 3px 10px #A6A6A6;
}
.btnSty:hover {
width: 20%;
height: 30px;
border-radius: 5px;
box-shadow: 3px 3px 10px #A6A6A6;
}
.userSty {
width: 25%;
height: 25px;
margin: 8px 18px 3px 18px;
border-radius: 5px;
box-shadow: 3px 3px 10px #A6A6A6;
}
.dd {
width: 135px;
height: 10px;
position: relative;
top: -10px;
font-size: 8px;
float: right;
clear: both;
}
.delbtn{
width: 35px;
height: 22px;
border-radius: 5px;
position: relative;
top: 5px;
right: -4px;
float: right;
z-index: 2;
color: red;
/* box-shadow: 2px 2px 3px #A6A6A6; */
}
</style>
</head>
<body>
<div class="mesDiv">
<input id="userId" class="userSty" type="button" value="您的姓名">
<input id="msgId" class="inputSty" type="text" placeholder="">
<input id="btnId" class="btnSty" type="button" value="提交留言">
</div>
<div class="bbslist cle" id="masMan">
<ul id="ulId">
<li>— — — 留言列表 — — —</li>
</ul>
</div>
<script type="text/javascript">
//定义一个函数用来重复获取gId("value"),中value的ID属性
function gId(n) {
return document.getElementById(n);
}
//获取姓名
gId("userId").onclick = function () {
var username = prompt("请输入您的姓名:");
alert("您好！" + username + "。");
gId("userId").value = username + "的留言：";
}
//删除留言
function delMsg(d) {
var parentUl = d.parentNode;
var parentDiv = parentUl.parentNode;
parentDiv.removeChild(parentUl);
}
//提交留言
gId('btnId').onclick = function () {
//获取时间
var today = new Date();
var year = today.getFullYear();
var month = today.getMonth() + 1;
var day = today.getDate();
var hours = today.getHours();
var min = today.getMinutes();
var second = today.getSeconds();
var time = year + "年" + month + "月" + day + "日" + " " + hours + "时" + min + "分" + second + "秒";
// var v = ;
if (gId('msgId').value === '') {
alert("留言不能为空");
return false;
}
//创建li
else {
//创建一个新元素ul
var ulcrate = document.createElement('ul');
//创建新元素li
var licrate = document.createElement('li');
//创建一个时间盒子
var divcrate = document.createElement('div');
//创建一个删除按钮
var delbtn = document.createElement('input');
//给删除按钮赋属性
delbtn.setAttribute('type', 'button');
delbtn.setAttribute('class', 'delbtn');
delbtn.setAttribute('value', '删除');
delbtn.setAttribute('onclick', 'delMsg(this)');
//给创建的ul赋属性
ulcrate.setAttribute('id', 'ulId');
//给时间盒子设置属性
// divcrate.setAttribute('class', 'dd');
divcrate.className = "dd";
//向li里添加在输入框中获取的值
licrate.innerHTML = gId('msgId').value;
//把，删除按钮，留言内容，时间盒子添加到创建的ul里
ulcrate.appendChild(delbtn);
ulcrate.appendChild(licrate);
ulcrate.appendChild(divcrate);
//给时间盒子传递时间
divcrate.innerHTML = time;
//把创建的ul添加到最外层的div里
gId('masMan').appendChild(ulcrate);
//留言内容初始化
gId("msgId").value = "";
}
}
</script>
</body>
</html>
