一些常用的js代码

//获取绝对路径 
function getUrl(path)
{
	var url = window.location.href;
	var r = url.match(/^http:\/\/[^\/:]*:\d*\/[\d\w]*\//);
	return (r==null?"":r[0]) + (path==null?"":path);
}

//初始化时间为月初
function getInitDate() {
	var myDate = new Date();
	var year = myDate.getFullYear();
	var month = myDate.getMonth() + 1;
	month = month < 10 ? ("0" + month) : month;
	return year + "-" + month + "-01";
}
//初始化时间为月初
function getFirstDate() {
	var myDate = new Date();
	var year = myDate.getFullYear();
	return year + "-01-01";
}
//初始化时间为年末
function getLastDate() {
	var myDate = new Date();
	var year = myDate.getFullYear();
	return year + "-12-31";
}
//初始化时间为当前时间
function getCurrDate(format) {
	var myDate = new Date();
	var year = myDate.getFullYear();
	var month = myDate.getMonth() + 1;
	var day = myDate.getDate();
	month = month < 10 ? ("0" + month) : month;
	day = day < 10 ? ("0" + day) : day;
	if(format == 'month')
		return year + month;
	return year + "-" + month + "-" + day;
}
//判断时间格式是否有效
String.prototype.isDate = function() {
	if (this == "")
		return true;
	var r = this.match(/^(\d{1,4})(-|\/)(\d{1,2})\2(\d{1,2})$/);
	if (r == null)
		return false;
	var d = new Date(r[1], r[3] - 1, r[4]);
	return (d.getFullYear() == r[1] && (d.getMonth() + 1) == r[3] && d
			.getDate() == r[4]);
}
//判断时间格式是否有效
String.prototype.isMonth = function() {
	return (this=="") || (null!= this.match(/^(\d{4})((0[\d])|(1[0,1,2]))$/));	
}
//判断是否整型
String.prototype.isInt = function() {
	return this.match(/^\d*$/) !=null;
}
//过滤字符串左右空格
String.prototype.trim = function() {
	return this.replace(/(^\s*)|(\s*$)/g, "");
}
//过滤字符串左边空格
String.prototype.ltrim = function() {
	this.replace(/(^\s*)/g, "");
}
//过滤字符串右边空格
String.prototype.rtrim = function() { 
	this.replace(/(\s*$)/g, "");
}

//根据checkBox的name获取被选中的value值，以，号隔开 
function getCheckBoxVal(name)
	{
		var val = '';
		$("input[@name=" + name + "][@checked]").each(function(){			
					if (val != "") 
					{
						val += ",";
					}        
					val += $(this).val();
		});
		return val;
	}
//校验证身证，自动将15位身份证转为18位
function validCardId(cardId)
{
	var ret = {err:""};
	var verifyArr = [1,0,"x",9,8,7,6,5,4,3,2];   
    var Wi = [7,9,10,5,8,4,2,1,6,3,7,9,10,5,8,4,2];   
	if(cardId.length != 15 && cardId.length != 18){
		ret.err="请输入15或者18位身份证号";
		return ret;
	}
	var Ai=cardId.length==18?cardId.substring(0,17):cardId.slice(0,6)+"19"+cardId.slice(6,16);   
	if (!/^\d+$/.test(Ai)){
		ret.err="身份证号错误";
		return ret;
	}
	var yyyy=Ai.slice(6,10),mm=Ai.slice(10,12)-1,dd=Ai.slice(12,14); 
	var birthday = yyyy+"-" + mm + "-" + dd;
	if(!birthday.isDate()){
		ret.err="身份证号日期错误";
		return ret;
	}
	for(var i=0,r=0;i<17;i++)  r+=Ai.charAt(i)*Wi[i];      
	var verify = verifyArr[r %=11];
     
	if(cardId.length ==18 && cardId.toLowerCase() != Ai){
		ret.err="身份证号校验码不符，为：" + verify;
		return ret;
	}
	ret.birthday = birthday;
	ret.gender= Ai[16]%2 ? "女":"男";
	ret.cardId= Ai + verify;  
    return ret;   
}