Help me to resolve this program? How to check date vaild or not? also tell me how to insert a month like jan,feb,etc

Question

import java.util.Scanner;

public class Date {

public static void main(String[] args) {

{

int dd,mm,yyyy,no_of_days=0;

Scanner sc=new Scanner(System.in);

System.out.println("enter month");

mm=sc.nextInt();

System.out.println("enter date");

dd=sc.nextInt();

System.out.println("enter year");

yyyy=sc.nextInt();

System.out.println("Date is:"+dd+"_"+mm+"_"+yyyy);

switch(mm)

{

case 1: case 3: case 5: case 7: case 8: case 10: case 12:

no_of_days=31;

if(mm<=12)

{

System.out.println("vaild month");

}

else

{

System.out.println("invaild month");

}

if(yyyy%4==0)

{

no_of_days=29;

System.out.println("leap year");

}

else {

System.out.println("not a leap year");}

if(dd<=31)

{

System.out.println("vaiild date");

}

else {

System.out.println("invaild date");}

break;

case 4: case 6: case 9: case 11:

no_of_days=30;

if(mm<=12)

{

System.out.println("vaild month")

Answer 1

Checkimg date is valid or not, use an array.
int[] days_in_month = {31, 29, 31, ...}

if(dd > days_in_month[mm+1]) //valid days
else // not valid days