来一波date工具函数

/**
 * 是否为闫年
 * @return {Boolse} true|false
 */
isLeapYear: function(y) {
    return (y % 4 == 0 && y % 100 != 0) || y % 400 == 0;
},

/**
 * 返回星期数
 * @return {Number}
 */
getWhatDay: function(year, month, day) {
    let date = new Date(year + '/' + month + '/' + day);
    let index = date.getDay();
    let dayNames = ['星期日', '星期一', '星期二', '星期三', '星期四', '星期五', '星期六'];
    return dayNames[index];
},

/**
 * 返回星期数
 * @return {Number}
 */
getMonthPreDay: function(year, month) {
    let date = new Date(year + '/' + month + '/01');
    let day = date.getDay();
    if (day == 0) {
        day = 7;
    }
    return day;
},

/**
 * 返回月份天数
 * @return {Number}
 */
getMonthDays: function(year, month) {
    if (/^0/.test(month)) {
        month = month.split('')[1];
    }
    return [0, 31, (this.isLeapYear(year) ? 29 : 28), 31, 30, 31, 30, 31, 31, 30, 31, 30, 31][month];
},

/**
 * 补齐数字位数
 * @return {string}
 */
getNumTwoBit: function(n) {
    n = Number(n);
    return (n > 9 ? '' : '0') + n;
},

/**
 * 日期对象转成字符串
 * @return {string}
 */
date2Str: function(date, split) {
    if (typeof date == 'string') return date;
    split = split || '-';
    let y = date.getFullYear();
    let m = this.getNumTwoBit(date.getMonth() + 1);
    let d = this.getNumTwoBit(date.getDate());
    return [y, m, d].join(split);
},

/**
 * 返回日期格式字符串
 * @param {Number} 0返回今天的日期、1返回明天的日期，2返回后天得日期，依次类推
 * @return {string} '2014-12-31'
 */
getDay: function (i) {
    i = i || 0;
    let date = new Date();
    let diff = i * (1000 * 60 * 60 * 24);
    date = new Date(date.getTime() + diff);
    return this.date2Str(date);
},

/**
 * 时间戳转换为日期格式
 * @return {String}
 */
timestampToDate: function (timestamp) {
    let date = new Date(timestamp);
    return date.getFullYear() + '-' + getNumTwoBit((date.getMonth() + 1)) + '-' + getNumTwoBit(date.getDate());
},

/**
 * 时间比较
 * @return {Boolean}
 */
compareDate: function (date1, date2) {
    let startTime = new Date(date1.replace('-', '/').replace('-', '/'));
    let endTime = new Date(date2.replace('-', '/').replace('-', '/'));
    if (startTime >= endTime) {
        return false;
    }
    return true;
},
/**
 * 时间是否相等
 * @return {Boolean}
 */
isEqual: function (date1, date2) {
    let startTime = new Date(date1).getTime();
    let endTime = new Date(date2).getTime();
    if (startTime == endTime) {
        return true;
    }
    return false;
}

export default Utils;