Commonly used methods for dates in javascript_time and date

1: Often involves date conversion comparison:

Copy code The code is as follows:

< html>

2: Date format judgment

Copy code The code is as follows:

//yyyy-MM-dd
if (!/^d{4}-dd?-dd?/.test(datavalue1)) {
alert("The date format of datevalue1 is illegal")
}
3: Convert week (extracted from others)
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util .Date;
public class TestDate {
public static String getWeekFromDate(String sDate,int type){
if("".equals(sDate)){
return "";
}
SimpleDateFormat df = null;
if(type==0){
df = new SimpleDateFormat("yyyy-MM-dd");
}else if(type==1){
df = new SimpleDateFormat("yyyyMMdd");
}
Date date = null;
try{
date = df.parse(sDate);
}catch(ParseException e) {
e.printStackTrace();
}
Calendar cd = Calendar.getInstance();
cd.setTime(date);
int mydate = cd.get(Calendar.DAY_OF_WEEK) ;
String showDate = "";
switch (mydate) { //mydate is 1---7: Sunday, Monday, Tuesday. . .
case 1:
showDate = "Sunday";
break;
case 2:
showDate = "Monday";
break;
case 3:
showDate = "Tuesday";
break;
case 4:
showDate = "Wednesday";
break;
case 5:
showDate = "Thursday";
break ;
case 6:
showDate = "Friday";
break;
default:
showDate = "Saturday";
break;
}
return showDate;
}
}