Js獲取明天、指定日期、本月第一天和最后一天

一、獲取日期

// 獲取日期方法（date為當天日期，i為相隔天數，例如：獲取明天日期，則將i=1傳入）
getDate (date, i) {
	if (date === undefined || date === null) {
		date = new Date();
	}
	let month, day;
	date.setTime(date.getTime() + i * 24 * 60 * 60 * 1000);
	month = date.getMonth() + 1 < 10 ? '0' + parseInt(date.getMonth() + 1) : date.getMonth() + 1;
	day = date.getDate() < 10 ? '0' + date.getDate() : date.getDate(); 
	let time = date.getFullYear() + "-" + month + "-" + day;
    return time;
}

二、獲取本月第一天和最后一天

   /**
     * 獲取本月第一天和最后一天
     */
    getMonthStartAndEndDate () {
      let nowDate = new Date()
      let nowYear = nowDate.getFullYear() // 當前年
      let nowMonth = nowDate.getMonth() // 當前月(值為0~11)
      let firstDate = new Date(nowYear, nowMonth, 1)
      let lastDate = new Date(nowYear, (nowMonth + 1), 0)
      let list = []
      list[0] = this.initDateFormat(firstDate)
      list[1] = this.initDateFormat(lastDate)
      return list
    },
   /**
     * 格式化時間數據
     */
    initDateFormat (date) {
      let month = date.getMonth() + 1 < 10 ? '0' + parseInt(date.getMonth() + 1) : date.getMonth() + 1
      let day = date.getDate() < 10 ? '0' + date.getDate() : date.getDate()
      return date.getFullYear() + '-' + month + '-' + day
    },

三、獲取指定月份的第一天和最后一天

/**
 * 獲取指定月份(格式：yyyy-MM)第一天和最后一天，例如：2022-06,2022-06-01 2022-06-30
 */
function getRequireMonthStartAndEndDate (month) {
  let index = month.lastIndexOf('-')
  let nowYear = parseInt(month.substr(0, index)) // 當前年
  let nowMonth = parseInt(month.substr(index + 1)) - 1 // 當前月(值為0~11)
  let firstDate = new Date(nowYear, nowMonth, 1)
  let lastDate = new Date(nowYear, (nowMonth + 1), 0)
  let list = []
  list[0] = initDateFormat(firstDate)
  list[1] = initDateFormat(lastDate)
  console.log(nowYear, nowMonth, firstDate, lastDate, list[0], list[1])
  return list
}

四、獲取本年第一天到本月最后一天

/**
 * 獲取本年第一天和到本月最后一天
 */
function getYearStartAndMonthEndDate () {
  let nowDate = new Date()
  let nowYear = nowDate.getFullYear() // 當前年
  let nowMonth = nowDate.getMonth() // 當前月(值為0~11)
  let firstDate = new Date(nowYear, 0, 1)
  let lastDate = new Date(nowYear, (nowMonth + 1), 0)
  let list = []
  list[0] = initDateFormat(firstDate)
  list[1] = initDateFormat(lastDate)
  return list
}