JavaScript

0x01 content introduction

Many friends will encounter various time related problems in the process of development, such as obtaining a specific time stamp, formatting the time object, etc. This article will help you to summarize and solve some common time problems. You can regard it as a dictionary article for future reference and use

0x02 time stamp

const date = new Date(); //Get time object
date.getTime(); //Get the current timestamp, the number of milliseconds from zero on January 1, 1970 to now
Math.round(date.getTime()/1000); //Gets the current timestamp, rounded to the nearest millisecond
Math.floor(date.getTime()/1000); //Get the current time stamp, and round it according to the number of milliseconds
Date.parse(date); // Get current timestamp, MS is 0

0x03 get date and time

let date = new Date();
let year = date.getFullYear();//Get the complete year (4 digits, 1970 -????)
let month = date.getMonth() + 1;//Get the current month (0-11,0 for January)
let day = date.getDate();//Get current day (1-31)
let weekDay = date.getDay();//Get current week X(0-6,0 for Sunday)
let hour = date.getHours();//Get current hours (0-23)
let minute = date.getMinutes();//Get current minutes (0-59)
let second = date.getSeconds();//Get current seconds (0-59)
let milliseconds = date.getMilliseconds();//Get the current number of milliseconds (0-999)

let setWeekDay = '';
switch (weekDay) {
  case 0:
    setWeekDay = 'Sunday';
    break;
  case 1:
    setWeekDay = 'Monday';
    break;
  case 2:
    setWeekDay = 'Tuesday';
    break;
  case 3:
    setWeekDay = 'Wednesday';
    break;
  case 4:
    setWeekDay = 'Thursday';
    break;
  case 5:
    setWeekDay = 'Friday';
    break;
  case 6:
    setWeekDay = 'Saturday';
    break;
}

console.log(`Today is ${year}year ${month}month ${day}day ${setWeekDay} ${hour}Time ${minute}branch ${second}second ${milliseconds}Millisecond`);

// The following three statements are the results of running in the Node environment. The results of running in the browser are different from this
date.toLocaleDateString();     //Acquisition date, YYYY-MM-DD
date.toLocaleTimeString();     //Get time, HH:mm:ss
date.toLocaleString();        //Get date and time, YYYY-MM-DD HH:mm:ss

0x04 actual combat

Requirement: write a general function or class to obtain the timestamp and time format of the current time or user-defined time, or realize the mutual conversion between the two

class Datetime {
  constructor(date) {
    if(date) {
      if (date instanceof Date) {
        this.date = date;
      } else {
        throw new Error('Constructor parameter error, expected Date()object')
      }
    } else {
      this.date = new Date();
    }
  }

  // Convert to timestamp
  transTimeStamp() {
    return this.date.getTime();
  }

  // Convert to time format YYYY-MM-DD HH:mm:ss
  transDateTime() {
    const {date, dateTimeFormat} = this;
    let year = date.getFullYear();//Get the complete year (4 digits, 1970 -????)
    let month = dateTimeFormat(date.getMonth() + 1);//Get the current month (0-11,0 for January)
    let day = dateTimeFormat(date.getDate());//Get current day (1-31)
    let hour = dateTimeFormat(date.getHours());//Get current hours (0-23)
    let minute = dateTimeFormat(date.getMinutes());//Get current minutes (0-59)
    let second = dateTimeFormat(date.getSeconds());//Get current seconds (0-59)
    return `${year}-${month}-${day} ${hour}:${minute}:${second}`
  }

  // Format
  dateTimeFormat(v) {
    return v < 10 ? `0${v}` : `${v}`
  }

  setDateTime(date) {
    if(date) {
      if (date instanceof Date) {
        this.date = date;
      } else {
        throw new Error('setDateTime Function parameter error, expected Date()object')
      }
    } else {
      this.date = new Date();
    }
  }
}

// Realization
const date = new Datetime();
console.log(date.transDateTime());
console.log(date.transTimeStamp());
date.setDateTime(new Date('2017-06-05 12:22:23'));
console.log(date.transDateTime());
console.log(date.transTimeStamp());