js实现生肖星座年龄余年计算

判断是否是余年

getSpecialDays(y) { // 判断是否是余年
    if (y % 400 == 0 || (y % 4 == 0 && y % 100 != 0)) { return 29 }
    return 28
},

生肖计算

getShengXiao(birth) { // 生肖计算
    birth += ''
    var len = birth.length
    if (len < 4 && len != 2) {
        return ''
    }
    if (len == 2) {
        birth - 0 > 30 ? birth = '19' + birth : birth = '20' + birth
    }
    var year = (new Date(birth)).getFullYear()
    var arr = ['猴', '鸡', '狗', '猪', '鼠', '牛', '虎', '兔', '龙', '蛇', '马', '羊']
    return /^\d{4}$/.test(year) ? arr[year % 12] : ''
},

星座计算

getAstro(m, d) { // 星座计算 getAstro(parseInt('09'), 26)
    return '魔羯水瓶双鱼白羊金牛双子巨蟹狮子处女天秤天蝎射手魔羯'.substr(m * 2 - (d < '102223444433'.charAt(m - 1) - -19) * 2, 2)
},

根据出生日期算出年龄

getAge(strBirthday) { // 根据出生日期算出年龄 getAge('1995-09-26')
    let returnAge
    const strBirthdayArr = strBirthday.split('-')
    const birthYear = strBirthdayArr[0]
    const birthMonth = strBirthdayArr[1]
    const birthDay = strBirthdayArr[2]
    const d = new Date()
    const nowYear = d.getFullYear()
    const nowMonth = d.getMonth() + 1
    const 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
},