如何使用JavaScript将日期添加到当前日期?JavaScript是否有像.NET的AddDay()那样的内置函数?


当前回答

我总结了小时和天。。。

Date.prototype.addDays = function(days){
    days = parseInt(days, 10)
    this.setDate(this.getUTCDate() + days);
    return this;
}

Date.prototype.addHours = function(hrs){
    var hr = this.getUTCHours() + parseInt(hrs  , 10);
    while(hr > 24){
      hr = hr - 24;
      this.addDays(1);
    }

    this.setHours(hr);
    return this;
}

其他回答

您可以使用以下选项创建一个:-

Date.prototype.addDays=函数(天){var date=新日期(this.valueOf());date.setDate(date.getDate()+天);返回日期;}var date=新日期();console.log(date.addDays(5));

这会在必要时自动增加月份。例如:

8/31+1天将变为9/1。

直接使用setDate的问题是它是一个赋值函数,最好避免这种情况。ECMA认为将Date视为一个可变的类而不是一个不可变的结构是合适的。

我的测试示例可以在日期对象的同一实例中执行减号。

Date.prototype.reset=函数(){let newDate=新日期(this.timeStamp)this.setFullYear(newDate.getFullYear)this.setMonth(newDate.getMonth())this.setDate(newDate.getDate())this.setHours(newDate.getHours())this.set分钟(newDate.getMinutes())this.setSeconds(newDate.getSeconds())this.set毫秒(newDate.getMilliseconds())}Date.prototype.addDays=函数(天){this.timeStamp=此[Symbol.toPrimitive]('编号')let daysInMiliseconds=(天*(1000*60*60*24))this.timeStamp=this.timeStamp+天毫秒this.reset()}Date.prototype.minusDays=函数(天){this.timeStamp=此[Symbol.toPrimitive]('编号')let daysInMiliseconds=(天*(1000*60*60*24))如果(daysInMiliseconds<=this.timeStamp){this.timeStamp=this.timeStamp-天毫秒this.reset()}}var temp=新日期(Date.now())//从现在开始console.log(temp.toDateString())临时添加天数(31)console.log(temp.toDateString())温度-天(5)console.log(temp.toDateString())

您可以在此处创建自定义助手函数

function plusToDate(currentDate, unit, howMuch) {

    var config = {
        second: 1000, // 1000 miliseconds
        minute: 60000,
        hour: 3600000,
        day: 86400000,
        week: 604800000,
        month: 2592000000, // Assuming 30 days in a month
        year: 31536000000 // Assuming 365 days in year
    };

    var now = new Date(currentDate);

    return new Date(now + config[unit] * howMuch);
}

var today = new Date();
var theDayAfterTommorow = plusToDate(today, 'day', 2);

顺便说一句,这是一个通用的解决方案,可以根据需要添加秒、分钟或天。

最简单的答案是,假设需要在当前日期上增加1天:

var currentDate = new Date();
var numberOfDayToAdd = 1;
currentDate.setDate(currentDate.getDate() + numberOfDayToAdd );

要逐行向您解释此代码的作用:

创建名为currentDate的当前日期变量。默认情况下,“new Date()”会自动将当前日期分配给变量。创建一个变量以保存要添加到日期的天数(您可以跳过此变量,直接使用第三行中的值)通过给定相同的值+所需的数字来更改Date的值(因为Date是保存在对象中的月份的日期)。切换到下个月将是自动的

一些扩展Date的实现https://gist.github.com/netstart/c92e09730f3675ba8fb33be48520a86d

/**
 * just import, like
 *
 * import './../shared/utils/date.prototype.extendions.ts';
 */
declare global {
  interface Date {
    addDays(days: number, useThis?: boolean): Date;

    addSeconds(seconds: number): Date;

    addMinutes(minutes: number): Date;

    addHours(hours: number): Date;

    addMonths(months: number): Date;

    isToday(): boolean;

    clone(): Date;

    isAnotherMonth(date: Date): boolean;

    isWeekend(): boolean;

    isSameDate(date: Date): boolean;

    getStringDate(): string;
  }
}

Date.prototype.addDays = function(days: number): Date {
  if (!days) {
    return this;
  }
  this.setDate(this.getDate() + days);
  return this;
};

Date.prototype.addSeconds = function(seconds: number) {
  let value = this.valueOf();
  value += 1000 * seconds;
  return new Date(value);
};

Date.prototype.addMinutes = function(minutes: number) {
  let value = this.valueOf();
  value += 60000 * minutes;
  return new Date(value);
};

Date.prototype.addHours = function(hours: number) {
  let value = this.valueOf();
  value += 3600000 * hours;
  return new Date(value);
};

Date.prototype.addMonths = function(months: number) {
  const value = new Date(this.valueOf());

  let mo = this.getMonth();
  let yr = this.getYear();

  mo = (mo + months) % 12;
  if (0 > mo) {
    yr += (this.getMonth() + months - mo - 12) / 12;
    mo += 12;
  } else {
    yr += ((this.getMonth() + months - mo) / 12);
  }

  value.setMonth(mo);
  value.setFullYear(yr);
  return value;
};

Date.prototype.isToday = function(): boolean {
  const today = new Date();
  return this.isSameDate(today);
};

Date.prototype.clone = function(): Date {
  return new Date(+this);
};

Date.prototype.isAnotherMonth = function(date: Date): boolean {
  return date && this.getMonth() !== date.getMonth();
};

Date.prototype.isWeekend = function(): boolean {
  return this.getDay() === 0 || this.getDay() === 6;
};

Date.prototype.isSameDate = function(date: Date): boolean {
  return date && this.getFullYear() === date.getFullYear() && this.getMonth() === date.getMonth() && this.getDate() === date.getDate();
};

Date.prototype.getStringDate = function(): string {
  // Month names in Brazilian Portuguese
  const monthNames = ['Janeiro', 'Fevereiro', 'Março', 'Abril', 'Maio', 'Junho', 'Julho', 'Agosto', 'Setembro', 'Outubro', 'Novembro', 'Dezembro'];
  // Month names in English
  // let monthNames = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];
  const today = new Date();
  if (this.getMonth() === today.getMonth() && this.getDay() === today.getDay()) {
    return 'Hoje';
    // return "Today";
  } else if (this.getMonth() === today.getMonth() && this.getDay() === today.getDay() + 1) {
    return 'Amanhã';
    // return "Tomorrow";
  } else if (this.getMonth() === today.getMonth() && this.getDay() === today.getDay() - 1) {
    return 'Ontem';
    // return "Yesterday";
  } else {
    return this.getDay() + ' de ' + this.monthNames[this.getMonth()] + ' de ' + this.getFullYear();
    // return this.monthNames[this.getMonth()] + ' ' + this.getDay() + ', ' +  this.getFullYear();
  }
};


export {};