js个人笔记
一、删除元素
<!DOCTYPE html>
<html>
<head>
<title>删除元素</title>
</head>
<body>
<ul>
<li>春</li>
<li>夏</li>
<li>秋</li>
<li>冬</li>
<li>中</li>
</ul>
<input type="button" value="点击删除最后一个li" onclick="d();">
<script type="text/javascript">
function d(){
var f = document.getElementsByTagName('li');
//var lis =
f[f.length-1].parentNode.removeChild(f[f.length-1]);
}
</script>
</body>
</html>
二、联动菜单
<!DOCTYPE html>
<html>
<head>
<title>
</title>
</head>
<body>
<select name = "" id = "prov" onchange="ld();">
<option value = '-1'>请选择</option>
<option value = '0'>北京</option>
<option value = '1'>山西</option>
</select>
<select name = "" id = "city" onchange="">
</select>
<script type="text/javascript">
var area = [['海淀','门头沟','大兴'],['太原','阳泉','晋城']];
function ld(){
var p = document.getElementById('prov');
//alert(p.value);
var opt = '';
if(p.value == '-1'){
document.getElementById('city').innerHTML = opt;
}
for(i=0;i<area[p.value].length;i++){
opt = opt + "<option>"+area[p.value][i]+"</option>";
}
document.getElementById('city').innerHTML = opt;
}
</script>
</body>
</html>>
三、计时器
<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<body>
<h1>定时器</h1>
<img src="./tp/0.gif">
<script type="text/javascript">
function bang(){
var ti = document.getElementsByTagName('input')[0];
var time = (parseInt(ti.value) - 1);
//console.log(time);
if(ti.value <=0){
document.getElementsByTagName('img')[0].src = "./tp/爱奇艺.png";
clearInterval(clock);
}
ti.value = time;
//document.getElementsByTagName('img')[0].src = "./tp/爱奇艺.png";
}
var clock = window.setInterval('bang()',1000);
//setTimeout
</script>
<input type="button" name="time" value = "5">
</body>
</html>
四、获得交点和失去交点
<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<body>
<input type="text" name="of" onfocus="f();" onblur="b();"><br><br>
<input type="text" name="of1"><br>
<script type="text/javascript">
function f(){
var f = document.getElementsByName('of')[0];
f.style.border = '1px solid red';
}
function b(){
var f = document.getElementsByName('of')[0];
f.style.border = '';
}
</script>
</body>
</html>
五、鼠标移至上方onmouseover
<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<body>
<style type="text/css">
div{
width: 200px;
height: 200px;
background: red;
}
</style>
<div onmouseover = 'ov();'></div>
<script type="text/javascript">
function ov(){
alert("huanyin");
}
</script>
</body>
</html>
六、提交事件onsubmit
<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<body>
<script type="text/javascript">
function ti(){
console.log('nihao');
//alert("qingtianxie");
//alert(document.getElementsByName('user')[0].value);
if(document.getElementsByName('user')[0].value == ""){
alert("please write userid");
return false;
}else{
return true;
}
}
</script>
<form action = "onsubmit.html" onsubmit="return ti();">
<input type="text" name="user"><br>
<input type="text" name="pass"><br>
<input type="submit" name="">
</form>
</body>
</html>
七、页面加载完成window.onload
<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<script type="text/javascript">
window.onload = function ti(){
document.getElementsByTagName('p')[0].style.border = '1px solid blue';
}
</script>
<body >
<p>
nihapo
</p>
</body>
</html>
八、事件对象（产生事件时产生的浏览器数据对象）
<!DOCTYPE html>
<html>
<head>
<title></title>
<style type="text/css">
img{
width: 130px;
height: 130px;
position: relative;
left: 0px;
top: 0px;
right: 0px;
}
</style>
<script type="text/javascript">
window.onload = function(){
document.getElementsByTagName('img')[0].onmouseover = function(ev){
//alert(ev);
console.log(ev);
this.style.left = ev.pageX+50+'px';
this.style.top = ev.pageY+50+'px';
}
}
</script>
</head>
<body>
<img src="./tp/0.gif" />
</body>
</html>
九、增加节点
<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<body>
<ul>
<li>春</li>
<li>夏</li>
<li>秋</li>
<li>冬</li>
<li>中</li>
</ul>
<input type="button" value="增加一个元素" onclick="creat();">
<script type="text/javascript">
function creat(){
var f = document.getElementsByTagName('ul')[0];
var s = document.createElement('li');
var txt = document.createTextNode('春天');
s.appendChild(txt);
f.appendChild(s);
}
</script>
</body>
十、利用事件委托的五子棋（实例化格子元素的父元素table，产生点击时的事件对象table.target中获取实际点击的对象）
<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<style type="text/css">
table{
width: 300px;
height: 300px;
border: 0;
border-collapse: collapse;
}
td{
border: 1px solid black;
background: green;
}
</style>
<body>
<table>
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
</table>
<script type="text/javascript">
/*var i = 0;
//alert(document.getElementsByTagName('td'));
while(i<document.getElementsByTagName('td').length){
document.getElementsByTagName('td')[i].onclick = function (){
this.style.background = 'black';
}
i++;
}*/
var sum = 0;
document.getElementsByTagName('table')[0].onclick = function (ev){
ev.target.style.background = sum++%2?'black':'white';
}
</script>
</body>
</html>
十一、正则验证邮箱exec方法
<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<body>
<ul>
<li>张飞</li>
<li>关羽<guanyu@qq.com></li>
<li>赵云</li>
<li>诸葛<zhuge@qq.com></li>
</ul>
<script type="text/javascript">
var lis = document.getElementsByTagName('li');
var i = 0;
console.log(lis[1].innerHTML);
while(i<lis.length){
var patt = /\w+@\w+(\.\w+)+/;
//alert('1');
if(patt.exec(lis[i].innerHTML) == null){
//alert('2');
lis[i].style.background = 'blue';
}i++;
}
//var txt = lis[i].innerHTML;
</script>
</body>
</html>
暂时就这么多。
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