js如何通过出生的年月日计算年龄

js如何通过出生的年月日计算年龄，下面web建站小编给大家详细介绍一下实现代码！

计算年龄方法：

function getAge(strBirthday){
  var returnAge;
  
  var strBirthdayArr=strBirthday.split("-");
  var birthYear = strBirthdayArr[0];
  var birthMonth = strBirthdayArr[1];
  var birthDay = strBirthdayArr[2];
 
  d = new Date();
  var nowYear = d.getFullYear();
  var nowMonth = d.getMonth() + 1;
  var nowDay = d.getDate();
 
  if(nowYear == birthYear){
    returnAge = 0;//同年 则为0岁
  }
  else{
    var ageDiff = nowYear - birthYear ; //年之差
    if(ageDiff > 0){
      if(nowMonth == birthMonth) {
        var dayDiff = nowDay - birthDay;//日之差
        if(dayDiff < 0){
          returnAge = ageDiff - 1;
        }else{
          returnAge = ageDiff ;
        }
      }else{
        var monthDiff = nowMonth - birthMonth;//月之差
        if(monthDiff < 0){
          returnAge = ageDiff - 1;
        }else{
          returnAge = ageDiff ;
        }
      }
    }
    else
    {
      returnAge = -1;//出生日期不能大于今天
    }
  }
  return returnAge;
}

获取周岁年龄：

console.log('获取周岁年龄：', getAge('1999-12-15'))
//获取周岁年龄： 23