本文实例讲述了JS根据生日算年龄的方法。分享给大家供大家参考。具体实现方法如下：

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; }}

希望本文所述对大家的javascript程序设计有所帮助。