JavaScript中有四种不同类型的循环，for循环、do-while循环和while循环。（第四种类型为for-in循环，用于迭代对象的属性，本文不予讨论。）代码如下：
var values = [1, 2, 3, 4, 5];
//for 循环
for(var i=0; i<values.length; i++){
process(values[i]);
}
//do-while 循环
var j=0;
do{
process(values[j++]);
} while(j < values.length);
//while 循环
var k=0;
while(k < values.length){
process(values[k++]);
}
每个循环示例都会得到相同的结果：将values数组的所有条目传送到process函数。
仔细观察会发现，代码中每次循环执行都会调用 values.length 查看是否到达数组尾部。调用 values.length 查看数组长度是非常低效的，并且在循环执行中并不会改变values数组的长度。 通过使用本地变量替代属性查找将会提高循环的效率。
var values = [1,2,3,4,5];
var length = values.length;
//for 循环
for(var i=0; i<length; i++){
process(values[i]);
}
//do-while 循环
var j=0;
do{
process(values[j++]);
} while(j < length);
//while 循环
var k=0;
while(k < length){
process(values[k++]);
}
现在每� ......
介绍两个关键的css
<style media="print">
.Noprint { DISPLAY: none }
.PageNext{ PAGE-BREAK-AFTER: always }
</style>第一个在不需要打印的标签上添加（子标签也将不被打印），第二个在需要换行的标签处添加（该标签所表示的内容将在当前打印的一页内）
接下来通过调用最基本的js语句
window.print()就可实现页面局部打印了，很easy吧！ ......
1. oncontextmenu="window.event.returnValue=false" 将彻底屏蔽鼠标右键
<table border oncontextmenu=return(false)> <td>no </table> 可用于Table
2. <body onselectstart="return false"> 取消选取、防止复制
3. onpaste="return false" 不准粘贴
4. oncopy="return false;" oncut="return false;" 防止复制
5. <link rel="Shortcut Icon" href="favicon.ico"> IE地址栏前换成自己的图标
6. <link rel="Bookmark" href="favicon.ico"> 可以在收藏夹中显示出你的图标
7. <input style="ime-mode:disabled"> 关闭输入法
8. 永远都会带着框架
<script language="JavaScript"> <!--
if (window == top)top.location.href = "frames.htm"; //frames.htm为框架网页
// --> </script>
9. 防止被人frame
<SCRIPT LANGUAGE=JAVASCRIPT> <!--
if (top.location != self.location)top.location=self.location;
// --> </SCRIPT>
10. 网页将不能被另存为
......
document.close();
document.open();
function jsonFormat(template, json) {
return template.replace(/\$\{(.+?)\}/g, function ($, $1) {
return json[$1];
});
}
var links = [
{ text: "人肉搜索", url: "http://renrousousuo.com" } ,
{ text: "CSDN", url: "http://www.csdn.net" } ,
{ text: "谷歌", url: "http://g.cn" } ,
{ text: "百度", url: "http://www.baidu.com" }
];
for (var i = 0; i < links.length; i++) {
document.write(
jsonFormat('<a href="${url}" mce_href="${url}" target="_blank">${text}</a><br/>', links[i])
);
}
function strFormat(template/*, ...*/) {
var arg = arguments;
return template.replace(/\{(\d+)\}/g, function ($, $1) {
return arg[+$1 + 1];
});
}
document.write(strFormat("<b>{0}</b> <i>{1}</i>！", "zswang", "路过"))
使用字符串格式化函数有什么� ......
<form name="form1">
<input type="file" name="file1" onchange="checkimage
(value)">
</form>
<script language="javascript">
var img=null;
function checkimage(name){
if(/^.+\.(gif|jpg|png)$/i.test(name))
{
if(img)img.removeNode(true);
img=document.createElement("img");
img.style.position="absolute";
img.style.visibility="hidden";
img.attachEvent("onerror",oe);
img.attachEvent("onreadystatechange",orsc);
document.body.insertAdjacentElement("beforeend",img);
img.src=name;
}
&nb ......
1，用户名不能包含空格，第一个字母不能为数字，长度控制
2，密码和验证码要相同，不能为空，等等，一些很基本的功能，但是确实挺烦人的。
javascript调试起来确实比较麻烦。
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
<script language = "javascript">
function ger_code(code_length) {
var rand_aa="";
var code=new Array("0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F","G","H","I","J",
"K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z","a","b","c","d","e","f","g","h",
"i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z","!","@","#","$","%","&",
"*","(",")","-","_","|","?","/");
var code_Num=code.l ......
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