【js】根据出生日期，计算周岁年龄

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/xuexiiphone/article/details/81005203

    /*根据出生日期算出年龄*/
    function jsGetAge(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;//返回-1 表示出生日期输入错误 晚于今天
            }
        }

        return returnAge;//返回周岁年龄

    }