JS根据生日算年龄的方法

function parseDate(str){
if(str.match(/^d{4}[-/s+]d{1,2}[-/s+]d{1,2}$/)){
return new Date(str.replace(/[-/s+]/i,'/'));
}
else if(str.match(/^d{8}$/)){
return new Date(str.substring(0,4)+'/'+str.substring(4,6)+'/'+str.substring(6));
}
else{
return ('时间转换发生错误！');
}
}
function GetAgeByBrithday(birthday){
var age=-1;
var today=new Date();
var todayYear=today.getFullYear();
var todayMonth=today.getMonth()+1;
var todayDay=today.getDate();
var birthday=parseDate(birthday);
if(parseDate(birthday)!='时间转换发生错误！')
{
birthdayYear=birthday.getFullYear();
birthdayMonth=birthday.getMonth();
birthdayDay=birthday.getDate();
if(todayYear-birthdayYear<0)
{
alert("出生日期选择错误!");
}
else
{
if(todayMonth*1-birthdayMonth*1<0)
{
age = (todayYear*1-birthdayYear*1)-1;
}
else
{
if(todayDay-birthdayDay>=0)
{//alert(thisDay+'-'+brithd+"_ddd");
age = (todayYear*1-birthdayYear*1);
}
else
{
age = (todayYear*1-birthdayYear*1)-1;
}
}
}
return age*1;
}
else
{
return -1;
}
}