<!DOCTYPE html>
<html>
<head>
<title>js的内置全局函数</title>
<script type="text/javascript">
//js的全局函数,内置一些函数
//encodeURIComponent/encodeURI 编码
//1.encodeURI 把url的中文改成%号形式
var url1 = 'http://www.baidu.com?key=中国'
console.log('url1:'+url1);
var url2 = encodeURI(url1);
console.log("url2:"+url2);
//2.不仅把url的中文改成%号形式,把特殊字符也改成%
var url3 = encodeURIComponent(url1);
console.log("url3:"+url3);
//3 j解码 encodeURI是编码 decodeURI是解码 类似于python中
var url4 = 'http%3A%2F%2Fwww.baidu.com%3Fkey%3D%E4%B8%AD%E5%9B%BD'
url5 = decodeURIComponent(url4);
console.log(url5);
//4 escape编码 unescape是解码
console.log(escape('中国'));
//5,eval 把字符串当js代码执行
var s = 'var i = 10;alert(i)';
eval(s);
</script>
</head>
<body>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<title>js方法</title>
<script type="text/javascript">
// js方法的声明 3种
/*第一种
function 函数名称(参数列表){
函数体;
}
js的方法:不需要声明返回值,参数不需要声明类型
*/
function add(a,b){
console.log(a+b);
}
add(1,2);//3
add("1",22); //122
/*第二种声明方式
var 函数名称=function(参数列表){
函数体;
}
*/
//把方法的引用传给了add1 类似于python
var add1 = function(a,b){
//打印a+b的值
console.log(a+b);
}
add1(112,123);
//声明有返回值的
function plus(a,b){
return a+b;
}
var r = plus(2,2);
console.log('r='+r);
</script>
</head>
<body>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<title>页面定时跳转页面</title>
<script type="text/javascript">
//开始倒计时
var timer;
var second = 5;
function start(){
//1.设置定时器
timer =sentInterVal(fuction(){
if (second ==1) {
//2结束定时器
clearInterval(timer);
//3.跳转到订单页面
open('./订单页面.html');
}
//显示span的内容
ducument.getElementById('time').innerHTML = second;
second -- ;
},1000);
}
//加载完后开始任务
windows.onload = function(){
start();
}
</script>
</head>
<body>
支付成功,<span id="time">5</span>秒后自动跳转订单页面
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<title>this关键字</title>
<script type="text/javascript">
windows.onload = function(){
//给div绑定了点击事件
document.getElementById('div1').onclick = function(){
//this 代表当前事件事件源
this.innerHTML = '点击' ;
}
}
</script>
</head>
<body>
<div id = "div1" style="width:100px;height: 100px;border:1px solid red;"></div>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<title>焦点事件</title>
<script type="text/javascript">
/*
onfoucus:获取焦点的事件
onblur:试求焦点
*/
function start(){
console.log('文本框编辑中...');
//通过id获取span标签
var spanTag = document.getElementByID('tip');
spanTag.innerHTML = '文本编辑中....'
}
function end(){
console.log('文本框编辑结束');
var spanTag = document.getElementByID('tip');
spanTag.innerHTML = '结束....'
}
</script>
</head>
<body>
用户:<input type="text" name="输入" placeholder="请输入用户名"onfocus =" start()"onblur="end()">
<span id="tip"></span>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<title>js的事件</title>
<script type="text/javascript">
//onclick:点击事件 //仿佛又回到了android
/*
按钮:事件源
点击:事件
方法:响应的行为
*/
function myclick(){
alert('想我了吗?');
}
//Onchange事件:改变
//改变区域
function changeDistrict(){
// alert('xxx');
//1.后去选中城市
//1.1 获取city的select标签
cityTag = document.getElementById('city');
// console.log(cityTag.value);
//1.2获取选中的值
var code = cityTag.value;
//1.3获取区域标签
var districtTag = document.getElementById ('district');
switch (code){
case 'gz':
districtTag.innerHTML = ' <option>天河区</option><option>越秀区</option><option>番禺区</option><option>黄浦区</option>'
break;
case 'sz':
districtTag.innerHTML = ' <option>1</option><option>2</option><option>3</option><option>4</option>'
break;
case 'zh':
districtTag.innerHTML = ' <option>11</option><option>5</option><option>6</option><option>7</option>'
break;
}
}
</script>
</head>
<body>
<button onclick="myclick()">点我有惊喜</button>
城市:<select name =" city" id = "city"onchange="changeDistrict()">
<option value="gz">广州</option>
<option value="sz">深圳</option>
<option value="zh">珠海</option>
</select>
区:<select id="district">
<option>天河区</option>
<option>越秀区</option>
<option>番禺区</option>
<option>黄浦区</option>
</select>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<title>js数据类型转换</title>
<script type="text/javascript">
//数据类型转换
//原始类型:string ,number ,booolean,undefined,null
var x = 12;
//在控制台打印 审查元素 console
console.log(typeof(x));
//把numer转成字符串
var y = x.toString();
console.log(typeof(y));
//2.转数字
var s1 = "12";
var b = parsenInt(s1)
console.log(typeof(b));
//3.强制类型转换
var a =0;
var xx = Boolean(a);
console.log(typeof(xx))
//3.1 把数据转成number
var s = '12';
var n = Number(s);
console.log(typeof(n));
//===:全等: 类型与值都要等于
//== 之哦按段值,不判断类型
var a = '20';
var b = 20;
console.log(a === b) //flase
//js也是有面向对象概念
var obj = new Object();
console.log(obj instanceof Object); //判断该对象是不是objcet类型的
//for 循环
for (var i = 0;i<10;i++){
console.log(i);
}
//for in 循环数组
console.log('====for in 循环数组')
var arr = [120,119,110];
for (idx in arr){
// 遍历出的idx 是个索引
console.log(arr[idx]) ;
}
</script>
</head>
<body>
</body>
</html>
