写代码

*
 *js HTML Encode
 */ 
var htmlEncode=function(str) {//HTML des encode.
    var res=[];
    for(var i=0;i < str.length;i++)
        res[i]=str.charCodeAt(i);
    return "&#"+res.join(";&#")+";";
};
 
var htmlEncode2=function(s) {
    var r = "", c;
    for (var i = 0; i < s.length; i++) {
        c = s.charCodeAt(i);
        r += (c < 32 || c == 38 || c > 127) ? ("&#" + c + ";") : s.charAt(i);
    }
    return r;
};
 
//s.replace(/([\u4e00-\u9fa5]+)/g,function($,$1) {
//    return htmlEncode($1);
//})
var htmlHexEncode=function(str) {//HTML hex encode.
    var res=[];
    for(var i=0;i < str.length;i++)
        res[i]=str.charCodeAt(i).toString(16);
    return "&#"+String.fromCharCode(0x78)+res.join(";&#"+String.fromCharCode(0x78))+";";//x ，防止ff下&#x 转义
};
 
var htmlDecode = function(str) {
    return str.replace(/&#(x)?([^&]{1,5});?/g,function($,$1,$2) {
        return String.fromCharCode(parseInt($2 , $1 ? 16:10));
    });
};
 
var s="htmlEncode HTML 编码转换 &#";
var s1=htmlEncode(s)+"\n\n只对双字节和&编码："+htmlEncode2(s);
var s2=htmlDecode(s1);
alert("编码前："+s+"\n\n编码后："+s1+"\n\n解码后："+s2);
 
var s="htmlHexEncode HTML 编码转换&#";
var s1=htmlHexEncode(s);
var s2=htmlDecode(s1);
alert("编码前："+s+"\n\n编码后："+s1+"\n\n解码后："+s2);

/*
 *js Unicode编码转换
 */ 
var decToHex = function(str) {
    var res=[];
    for(var i=0;i < str.length;i++)
        res[i]=("00"+str.charCodeAt(i).toString(16)).slice(-4);
    return "\\u"+res.join("\\u");
}
 
var decToHex2 = function(str) {
    var res="",c;
    for(var i=0;i < str.length;i++){
        c=str.charCodeAt(i);
        res+=(c< 32 || c==38 || c>127)?"\\u"+c.toString(16):str.charAt(i)
    }
    return res
}
 
var hexToDec = function(str) {
    str=str.replace(/\\/g,"%");
    return unescape(str);
}
 
var str=decToHex2("decToHex unicode 编码转换");
alert("编码后："+str+"\n\n解码后："+hexToDec(str));

//lastest:
var getArgs=function() {//get url querystring
    var params=document.location.search,reg=/(?:^\?|&)(.*?)=(.*?)(?=&|$)/g,temp,args={};
    while((temp=reg.exec(params))!=null) args[temp[1]]=decodeURIComponent(temp[2]);
    return args;
};
//只取一个：
var queryString=function(key){
    return (document.location.search.match(new RegExp("(?:^\\?|&)"+key+"=(.*?)(?=&|$)"))||['',null])[1];
}
var args=getArgs();
alert(args.name+" | "+args.sex+" | "+args.age);
//测试链接：< a href="?name=abc&sex=男&age=12">test getQueryString
 
//deprecated
var getArgs=function() {
    var params=document.location.search.substr(1),reg=/(?:^|&)(.*?)=(.*?)(?:&|$)/g,temp,args={};
    while((temp=reg.exec(params))!=null) {        
        args[temp[1]]=temp[2];
        reg.lastIndex-=1;//减1，下一次从结束的&开始匹配
    }
    return args;
};
var getArgs=function(){
    var sarg = document.location.search.substr(1),rv={};
    rv.filename = document.location.pathname.replace(/.*\//ig,'');
    if(!sarg){return rv;}
    var aarg = sarg.split('&'),atmp=[];
    for(var i=0;i< aarg.length;i++){
        atmp = aarg[i].split('=');
        rv[atmp[0]] = unescape(atmp[1]);
    }
    return rv;
};

<input type="file" onchange="checkExt(this)"/>

function checkExt(file) {
    if(!(/(?:jpg|gif)$/i.test(file.value))) {
        alert("只允许上传jpg和gif的图片");
        if(window.ActiveXObject) { //for IE
            file.select();  //select the file ,and clear selection
            document.selection.clear();
        } else if(window.opera) {  //for opera
            file.type="text";file.type="file";
        } else file.value="";  //for FF,Chrome,Safari
    } else {
        alert("ok");  //or you can do nothing here.
    }
};

var getScriptArgs=function(){ //获取多个参数
    var scripts=document.getElementsByTagName("script"),
    script=scripts[scripts.length-1], //因为当前dom加载时后面的script标签还未加载，所以最后一个就是当前的script
    src=script.src,
    reg=/(?:\?|&)(.*?)=(.*?)(?=&|$)/g,
    temp,res={};
    while((temp=reg.exec(src))!=null) res[temp[1]]=decodeURIComponent(temp[2]);
    return res;
};
 
var args=getScriptArgs();
alert(args.a+" | "+args.b+" | "+args.c);
 
//假如上面的js是在这个xiedaima.js的脚本中
< script type="text/javascript" src="xiedaima.js?power=xiedaima&by=写代码&domian=xiedaima.cn">< /script>
 
var getScriptArg=function(key){ //获取单个参数
    var scripts=document.getElementsByTagName("script"),
    script=scripts[scripts.length-1],
    src=script.src;
    return (src.match(new RegExp("(?:\\?|&)"+key+"=(.*?)(?=&|$)"))||['',null])[1];
};
 
alert(getScriptArg("domain"));

//获得当前script文件的路径
function getScriptPath(){
    try {
        throw Error("获取路径")
    }catch(ex){
        if(ex.fileName) //Firefox
            strJsPath=ex.fileName
        else if(ex.stack) //Chrome
            strJsPath=(ex.stack.match(/at\s+(.*?):\d+:\d+/)||['',''])[1];
        else if(ex.sourceURL) //Safari
            strJsPath=ex.sourceURL 
    }
    if(strJsPath)return; //其实所有浏览器都可以用下面的
    var scripts=document.getElementsByTagName("script"),script=scripts[scripts.length-1];
    strJsPath=document.querySelector?script.src:script.getAttribute("src",4) //IE8直接.src
}

//取元素坐标
function getPos(o){
    var x = 0, y = 0;
 
    do{
        x += o.offsetLeft;
        y += o.offsetTop;
    }while(o=o.offsetParent);
 
    return {'x':x,'y':y};
}