javascript 常用验证函数

/**
* 去掉左右空格
*/
String.prototype.trim=function()
{
     return this.replace(/^\s+|\s+$/g,"");
}
/**
* 去掉左边空格
*/
String.prototype.ltrim=function()
{
     return this.replace(/^\s+/,"");
}
/**
* 去掉右边空格
*/
String.prototype.rtrim=function()
{
     return this.replace(/\s+$/,"");
}
/**
* 获得左边字符串
*/
String.prototype.left = function(len)
{
if(isNaN(len)||len==null)
{
len = this.length;
}
else
{
if(parseInt(len)<0||parseInt(len)>this.length)
{
len = this.length;
}
}
return this.substring(0,len);
}


/**
* 获得右边字符串
*/
String.prototype.right = function(len)
{
if(isNaN(len)||len==null)
{
len = this.length;
}
else
{
if(parseInt(len)<0||parseInt(len)>this.length)

{
len = this.length;
}

}

return this.substring(this.length-len,this.length);
}


/**
* 获得中间字符串
*/
String.prototype.mid = function(start,len)
{

     return this.substring(start,len);
}

/**
* 返回字符串所在的位置
*/
String.prototype.instr = function(str)
{
if(str==null)
{
str = "";
}

    return this.indexOf(str);
}

/**
* 验证是否是IP
*/
String.prototype.isIP = function()
{
var reSpaceCheck = /^(\d+)\.(\d+)\.(\d+)\.(\d+)$/;

if (reSpaceCheck.test(this))
{

this.match(reSpaceCheck);

if (RegExp.$1 <= 255 && RegExp.$1 >= 0

&& RegExp.$2 <= 255 && RegExp.$2 >= 0

&& RegExp.$3 <= 255 && RegExp.$3 >= 0

&& RegExp.$4 <= 255 && RegExp.$4 >= 0)
{
return true;    
}
else
{
return false;
}
}
else
{
return false;
}
}

/**
*验证是否是手机号
*/
String.prototype.isMobile = function()
{
return /^0{0,1}13[0-9]{9}$/.test(this);
}

/**
* 验证是否是E-Mail
*/
String.prototype.isEmail = function()
{
    return /^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/.test(this);
}

/**
*验证是否存在汉字
*/
String.prototype.existChinese = function()
{
return /^[\x00-\xff]*$/.test(this);

}

/**
*验证是否是正确的身份证号
*/
String.prototype.isIDCard = function()
{
var iSum=0;
    var info="";
    var sId = this;

    var aCity={11:"北京",12:"天津",13:"河北",14:"山西",15:"内蒙古",21:"辽宁",22:"吉林",23:"黑龙江",31:"上海",32:"江苏",33:"浙江",34:"安徽",35:"福建",36:"江西",37:"山东",41:"河南",42:"湖北",43:"湖南",44:"广东",45:"广西",46:"海南",50:"重庆",51:"四川",52:"贵州",53:"云南",54:"西藏",61:"陕西",62:"甘肃",63:"青海",64:"宁夏",65:"新疆",71:"台湾",81:"香港",82:"澳门",91:"国外"};

    if(!/^\d{17}(\d|x)$/i.test(sId))
    {
            return false;
    }
    sId=sId.replace(/x$/i,"a");
    //非法地区
    if(aCity[parseInt(sId.substring(0,2))]==null)
    {
            return false;
    }

    var sBirthday=sId.substring(6,4)+"-"+Number(sId.substring(10,2))+"-"+Number(sId.substring(12,2));

    var d=new Date(sBirthday.replace(/-/g,"/"))
   
    //非法生日
    if(sBirthday!=(d.getFullYear()+"-"+ (d.getMonth()+1) + "-" + d.getDate()))
    {
            return false;
    }
    for(var i = 17;i>=0;i--)
    {
            iSum += (Math.pow(2,i) % 11) * parseInt(sId.charAt(17 - i),11);
    }

    if(iSum%11!=1)
    {
            return false;
    }
   
    return true;
}

/**
* 验证是否是正确的电话号码
*/
String.prototype.isPhoneCall = function()
{
        return /(^[0-9]{3,4}\-[0-9]{3,8}$)|(^[0-9]{3,8}$)|(^\([0-9]{3,4}\)[0-9]{3,8}$)|(^0{0,1}13[0-9]{9}$)/.test(this);
}

/**
* 验证是否是数字
*/
String.prototype.isNumeric = function(flag)
{
if(isNaN(this))
     {

             return false;
     }

     switch(flag)
     {

             case null:        //数字
             case "":
                     return true;
             case "+":        //正数
                     return                /(^\+?|^\d?)\d*\.?\d+$/.test(this);
             case "-":        //负数
                     return                /^-\d*\.?\d+$/.test(this);
             case "i":        //整数
                     return                /(^-?|^\+?|\d)\d+$/.test(this);
             case "+i":        //正整数
                     return                /(^\d+$)|(^\+?\d+$)/.test(this);                       
             case "-i":        //负整数
                     return                /^[-]\d+$/.test(this);
             case "f":        //浮点数
                     return                /(^-?|^\+?|^\d?)\d*\.\d+$/.test(this);
             case "+f":        //正浮点数
                     return                /(^\+?|^\d?)\d*\.\d+$/.test(this);                       
             case "-f":        //负浮点数
                     return                /^[-]\d*\.\d$/.test(this);               
             default:        //缺省
                     return true;                       
     }
}

/**
*是否是颜色(#FFFFFF形式)
*/
String.prototype.IsColor = function()
{
        var temp        = this;
        if (temp=="") return true;
        if (temp.length!=7) return false;

        return (temp.search(/\#[a-fA-F0-9]{6}/) != -1);
}

/**
*对字符串进行Html编码
*/
String.prototype.toHtmlEncode = function()
{
        var str = this;

        str=str.replace(/&/g,"&amp;");

        str=str.replace(/</g,"&lt;");

        str=str.replace(/>/g,"&gt;");

        str=str.replace(/\'/g,"&apos;");

        str=str.replace(/\"/g,"&quot;");

        str=str.replace(/\n/g,"<br>");

        str=str.replace(/\ /g,"&nbsp;");

        str=str.replace(/\t/g,"&nbsp;&nbsp;&nbsp;&nbsp;");

        return str;
}