摘要：獲得某月的天數(shù)獲得本季度的開始月份獲得今天之前的日期獲得今天之后的日期獲得本周的開始日期獲得本周的結(jié)束日期獲得上周的開始日期獲得上周的結(jié)束日期獲得本月的開始日期獲得本月的結(jié)束日期獲得本季度的開始日期獲得本季度的結(jié)束日期

最近項(xiàng)目中遇到一個(gè)問題, 提交后的時(shí)間后臺(tái)會(huì)返回"2018-01-05T17:32:03"這樣的一個(gè)時(shí)間格式, 在展示的是則只需要展示"2018-01-05". 這種需求應(yīng)該有很多種方法, 這里我列舉兩個(gè).

強(qiáng)行截取: substr(0, 10); 任意截取方法

時(shí)間格式化: 通過new Date() 方法格式化時(shí)間

詳細(xì)說一個(gè)第二種時(shí)間格式化的問題
初始時(shí)只寫了最簡(jiǎn)單時(shí)間格式化方法:

formatDate(date) {
    const _date = date ? new Date(date) : new Date(); // 這里判斷是否有傳入的時(shí)間, 如果沒有時(shí)間則創(chuàng)建當(dāng)前時(shí)間
    const _y = _date.getFullYear(),
          _m = _date.getMonth() + 1,
          _d = _date.getDate();
          
    if(_m < 10) {
        _m = `0${_m}`
    };
    
    if(_d < 10) {
        _d = `0${_d}`
    };
    
    return +`${_y}-${_m}-${_d}`;
}

這樣寫是有瀏覽器兼容性問題的, 就拿"2018-01-05T17:32:03"這個(gè)事件來說, 在QQ瀏覽器下格式化的時(shí)間會(huì)是"2018-01-06", 解決這個(gè)問題在格式化時(shí)要替換掉時(shí)間中的"T"字符, 當(dāng)我以為這樣就很穩(wěn)妥時(shí)我打開了一下ie瀏覽器結(jié)果發(fā)現(xiàn)格式化后的時(shí)間都為NAN了, 又去查找癥結(jié)所在.
在IE和Safari時(shí)間轉(zhuǎn)化時(shí)間戳?xí)r"yyyy-mm-dd"是不能轉(zhuǎn)化為時(shí)間戳, 需要"yyyy/mm/dd hh:ii:ss"格式才能正取轉(zhuǎn)化.
下面給出完整代碼:

export default class DateChoice {

    /** 
    @agruments config {
        s: "-", // 格式化時(shí)間分隔符 默認(rèn)為"-"
    }
    **/
    constructor(config = {}) {
        this.s = config.s || (config.s === "" ? "" : "-");

        this.now = new Date(); // 當(dāng)前日期
        this.nowDayOfWeek = this.now.getDay() - 1; // 今天本周的第幾天
        this.nowDay = this.now.getDate(); // 當(dāng)前日
        this.nowMonth = this.now.getMonth() + 1; // 當(dāng)前月
        this.nowYear = this.now.getYear(); // 當(dāng)前年
        this.nowYear += (this.nowYear < 2000) ? 1900 : 0; //

        this.lastMonthDate = new Date(); //上月日期
        this.lastMonthDate.setDate(1);
        this.lastMonthDate.setMonth(this.lastMonthDate.getMonth() - 1);
        this.lastYear = this.lastMonthDate.getYear();
        this.lastMonth = this.lastMonthDate.getMonth();
    }

    // 格式化日期：yyyy-MM-dd    @argument date 不傳則獲取今天日期
    formatDate(date){
        if(typeof date === "string" && date.includes("T")) {
            date = date.replace("T", " ").replace(/-/g, "/"); //注意：指定一個(gè)具體的時(shí)間轉(zhuǎn)換時(shí)間戳，需要yyyy/mm/dd hh:ii:ss格式，yyyy-mm-dd在IE和Safari下是有問題的。
        };
        const D = date ? new Date(date) : new Date();
        
        let myyear = D.getFullYear();
        let mymonth = D.getMonth() + 1;
        let myweekday = D.getDate();
        if (mymonth < 10) {
            mymonth = "0" + mymonth;
        }
        if (myweekday < 10) {
            myweekday = "0" + myweekday;
        }
        return (myyear + this.s + mymonth + this.s + myweekday);
    }


    // 獲得某月的天數(shù)
    getMonthDays(myMonth) {
        const monthStartDate = new Date(this.nowYear, myMonth - 1, 1);
        const monthEndDate = new Date(this.nowYear, myMonth, 1);
        const days = (monthEndDate - monthStartDate) / (1000 * 60 * 60 * 24);
        return days;
    }

    // 獲得本季度的開始月份
    getQuarterStartMonth() {
        let quarterStartMonth = 1;
        if (this.nowMonth < 4) {
            quarterStartMonth = 1;
        }
        if (3 < this.nowMonth && this.nowMonth < 7) {
            quarterStartMonth = 4;
        }
        if (6 < this.nowMonth && this.nowMonth < 10) {
            quarterStartMonth = 7;
        }
        if (this.nowMonth > 9) {
            quarterStartMonth = 10;
        }
        return quarterStartMonth;
    }

    // 獲得今天之前的日期
    getTodayBeforeDate(num) {
        const beforeDate = new Date(this.nowYear, this.nowMonth - 1, this.nowDay - num);
        return this.formatDate(beforeDate);
    }

    // 獲得今天之后的日期
    getTodayAfterDate(num) {
        const afterDate = new Date(this.nowYear, this.nowMonth - 1, this.nowDay + num);
        return this.formatDate(afterDate);
    }

    // 獲得本周的開始日期
    getWeekStartDate() {
        const weekStartDate = new Date(this.nowYear, this.nowMonth - 1, this.nowDay - this.nowDayOfWeek);
        return this.formatDate(weekStartDate);
    }

    // 獲得本周的結(jié)束日期
    getWeekEndDate() {
        const weekEndDate = new Date(this.nowYear, this.nowMonth - 1, this.nowDay + (6 - this.nowDayOfWeek));
        return this.formatDate(weekEndDate);
    }

    // 獲得上周的開始日期
    getLastWeekStartDate() {
        const weekStartDate = new Date(this.nowYear, this.nowMonth - 1, this.nowDay - this.nowDayOfWeek - 7);
        return this.formatDate(weekStartDate);
    }

    // 獲得上周的結(jié)束日期
    getLastWeekEndDate() {
        const weekEndDate = new Date(this.nowYear, this.nowMonth - 1, this.nowDay - this.nowDayOfWeek - 1);
        return this.formatDate(weekEndDate);
    }

    // 獲得本月的開始日期
    getMonthStartDate() {
        const monthStartDate = new Date(this.nowYear, this.nowMonth - 1, 1);
        return this.formatDate(monthStartDate);
    }

    // 獲得本月的結(jié)束日期
    getMonthEndDate() {
        const monthEndDate = new Date(this.nowYear, this.nowMonth - 1, this.getMonthDays(this.nowMonth));
        return this.formatDate(monthEndDate);
    }

    // 獲得本季度的開始日期
    getQuarterStartDate() {
        const quarterStartDate = new Date(this.nowYear, this.getQuarterStartMonth() - 1, 1);
        return this.formatDate(quarterStartDate);
    }

    // 獲得本季度的結(jié)束日期
    getQuarterEndDate() {
        const quarterEndMonth = this.getQuarterStartMonth() + 2;
        const quarterStartDate = new Date(this.nowYear, quarterEndMonth - 1, this.getMonthDays(quarterEndMonth));
        return this.formatDate(quarterStartDate);
    }

}