How do i take the user inputted day, month and year then store in a dd-mm-yyyy format? I can get everything to work except combining them into a date and storing them in the startDate variable. I also don't think startMonth will be accessible as it's in a switch case but I'm very new to java and unsure.
public static void carBookingDates() {
int carNumber;
int startYear;
int startDay;
int startMonth;
int daysInMonth = 0;
int endYear;
int endMonth;
int endDay;
Scanner input = new Scanner(System.in);
System.out.println("To make a booking:");
System.out.printf(" Select a car number from the car list: ");
carNumber = input.nextInt();
System.out.println("");
System.out.println("Enter a booking start date.");
System.out.printf("Please enter the year - for example '2022': ");
startYear = input.nextInt();
while (startYear < 2022 || startYear > 2030) {
System.out.println("Invalid year, please try again: ");
System.out.printf("Please enter the year - for example '2022': ");
startYear = input.nextInt();
}
System.out.printf("Please enter the month - for example '6': ");
startMonth = input.nextInt();
while (startMonth < 1 || startMonth > 12) {
System.out.println("Invalid month, please try again: ");
System.out.printf("Please enter the month - for example '6': ");
startMonth = input.nextInt();
}
switch (startMonth) {
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
daysInMonth = 31;
break;
case 4:
case 6:
case 9:
case 11:
daysInMonth = 30;
break;
case 2:
if (((startYear % 4 == 0)
&& !(startYear % 100 == 0))
|| (startYear % 400 == 0)) {
daysInMonth = 29;
} else {
daysInMonth = 28;
}
break;
default:
System.out.println("Invalid month.");
break;
}
System.out.printf("Please enter the day number - for"
+ " example '18': ");
startDay = input.nextInt();
while (startDay > daysInMonth || startDay <= 0) {
System.out.println("Invalid day, plese try again");
System.out.printf("Please enter the day number - for"
+ " example '18': ");
startDay = input.nextInt();
LocalDate startDate() = LocalDate.parse(startDay + "-" + StartMonth "-" + startYear);
}
}
First of all, you can use the Java 8 Date Time API to get the number of days in a month instead of using a manual switch case for making the code more readable.
import java.time.YearMonth;
Then:
// 2021 is the year and 2 is the month
int daysInMonth = YearMonth.of(2021,2).lengthOfMonth());
Now to form the date in dd-mm-yyyy format :
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
Then:
// pass your date value here under LocalDate.of method
LocalDate.of(2021,2,16).format(DateTimeFormatter.ofPattern("dd-MM-yyyy"));
Related
import java.util.Scanner;
public class DaysInMonth
{
public static void main(String[] args)
{
Scanner input = new Scanner(System.in);
System.out.print("Enter a year:")
int year = input.nextInt(); enter code here
System.out.print("Enter a month:");
int month = input.nextInt(); enter code here
int days = 0;
boolean isLeapYear = (year % 4 == 0 && year % 100 != 0)||(year % 400 == 0);
switch (month){
case 1:
days = 31;
break;
case 2:
if (isLeapYear)
days = 29;
else
days = 28;
break;
case 3:
days = 31;
break;
case 4:
days = 30;
break;
case 5:
days = 31;
break;
case 6:
days = 30;
break;
case 7:
days = 31;
break;
case 8
days = 31;
break;
case 9:
days = 30;
break;
case 10:
days = 31;
break;
case 11:
days = 30;
break;
case 12:
days = 31;
break;
default:
String response = "Have a Look at what you've done and try again";
System.out.println(response);
System.exit(0);
}
String response = "There are " +days+ " Days in Month "+month+ " of Year " +year+ ".\n";
System.out.println(response); // new line to show the result to the screen.
}
}
Why can't I type in January to get the same output result if I type 1? It should print "There are 31 days in the month of January of Year 2018" I initialized the month so it should read January or any other month.
I know I have int but I am wondering how can I also use January for 1 to get the same output.
You can use Strings in a switch statement to check for several equivalent cases:
switch (monthInput.toLowerCase()) {
case "january":
case "jan":
case "1":
days = 31;
break;
case "february":
case "feb":
case "2":
days = isLeapYear ? 29 : 28;
break;
case "march":
case "mar":
case "3":
days = 31;
break;
// etc.
default:
System.out.println(monthInput + " is not a valid month");
input.close();
System.exit(0);
}
But this means you have to read your input as a String, not as an int...
Scanner input = new Scanner(System.in);
System.out.print("Enter a year:");
int year = input.nextInt(); // enter code here
input.nextLine(); // read the rest of the line (if any)
System.out.print("Enter a month:");
String monthInput = input.nextLine();
Note the use of input.nextLine(); after the .nextInt() — this is because the nextInt() call does not consume all of the input, it only reads the int that you typed for the Year, it does not read the newline (enter key), so you have to read that to be ready to read the next input, which is the month number or name.
I know I have int but I am wondering how can I also use January for 1 to get the same output.
A simple approach is to use name array
// before main.
static final String[] MONTH = "?,Jan,Feb,Mar,Apr,Jun,Jul,Aug,Sep,Oct,Nov,Dec".split(",");
// inside main
String monthStr = MONTH[month];
Add the full month names as needed.
I need to know which day and day name is on a specific date. And somehow I made a mistake because for years with 19.. it works but at 2000 I can't get the right day anymore. For example if I use the date 9.1.2001 it doesn't say me the day, instead the error of the switch I made occurs.
and i shouldn't use the calendar methods
here is my code:
public class FindDay {
public static void main(String[] args) {
System.out.println("Type a day: ");
int day = In.readInt();
System.out.println("Type a month: ");
int month = In.readInt();
System.out.println("Type a year: ");
int year = In.readInt();
if(day < 1 || day > 32) {
System.out.println("Type valid day");
}else if (month < 1 || month >12) {
System.out.println("Type valid month");
}else if (year < 1900) {
System.out.println("Type valid year");
}
int wholeDaysYear; //to calculate how much days a year has
if (year % 4 == 0 && !(year % 100 == 0 && year % 400 != 0) ) {
wholeDaysYear = 366;
}else {
wholeDaysYear = 365;
}
int monthDays = 0; //calculates days to this month
int february; //if February has 28 or 2 days
if(wholeDaysYear ==366) {
february = 29;
}else {
february = 28;
}
switch(month) {
case 1: monthDays= 0; break;
case 2: monthDays =31; break;
case 3: monthDays= 31+february; break;
case 4: monthDays= 31+february+31; break;
case 5: monthDays= 31+february+31+30; break;
case 6: monthDays= 31+february+31+30+31; break;
case 7: monthDays= 31+february+31+30+31+30; break;
case 8: monthDays= 31+february+31+30+31+30+31; break;
case 9: monthDays= 31+february+31+30+31+30+31+31; break;
case 10: monthDays= 31+february+31+30+31+30+31+31+30; break;
case 11: monthDays= 31+february+31+30+31+30+31+31+30+31; break;
case 12: monthDays= 31+february+31+30+31+30+31+31+30+31+30; break;
default: System.out.println("Enter valid month!");break;
}
int leapYear = ((year-1) / 4 - 474) - ((year-1) / 100 - 18) + ((year-1) / 400 - 4); //calculates the leap years
int allDays =(((year - leapYear)-1900)*wholeDaysYear)+monthDays+day-1; //Calculates all days
System.out.println(allDays);
int dayName = allDays % 7;
String dayNames = null; //gives the days their name
switch (dayName) {
case 1: dayNames = "Monday";break;
case 2: dayNames = "Tuesday";break;
case 3: dayNames = "Wendesday";break;
case 4: dayNames = "Thursday";break;
case 5: dayNames = "Friday";break;
case 6: dayNames = "Saturday";break;
case 7: dayNames = "Sunday";break;
default: System.out.println("Type valid Input");break;
}
System.out.println(dayNames);
}
}
You don't have to work so hard... assuming you have the day of the month, month of the year and full-year, you can simply do (example):
LocalDate ld = LocalDate.of(1999, 12, 12);
System.out.println(ld.getDayOfWeek()); // prints SUNDAY
LocalDate is available since Java 8.
As for your code, two bugs that are easy to spot are:
The cases in the switch go from 1 to 7 while they should go from 0 to 6 since you're calculating the reminder out of 7.
int dayName = allDays % 7; here you assume that the first day of the year is Monday (according to your case switch) which is not necessarily true.
You can try something like this:
Date yourDate;
Calendar cal = Calendar.getInstance();
cal.setTime(yourDate);
int year = cal.get(Calendar.YEAR);
int month = cal.get(Calendar.MONTH);
int day = cal.get(Calendar.DAY_OF_MONTH); //or Calendar.DAY_OF_WEEK
// etc.
I am currently trying to finish this program, however when I am testing my switch statement, it goes directly to my default case and says that I have entered invalid information.
My Task
I have to receive a month from the user and send it to my case statement in order to execute my code for the certain case. As you may notice, that each case has a key in it, this key is for personal purposes. Please disregard.
My Problem
case statement goes directly into my default statement, which issues an invalid information message to the user.
My Progress
This will be my complete program, everything seems to work properly except that my case statement recognizes every month as invalid input
// Import Libraries
import javax.swing.*;
import java.util.*;
import java.io.*;
// This is my program.
public class DateCalc
{
public static void main (String[] args)
{
String month;
String day;
String inputYear;
Scanner keyboard = new Scanner(System.in);
// receiving input for my age variable
System.out.print( "Please Enter The Month Of The Date :");
month = keyboard.nextLine();
// receiving input for my weight variable
System.out.print( "Please Enter The Day Of The Date : ");
day = keyboard.nextLine();
// receiving input for my height variable
System.out.print( "Please Enter The Year OF The Date : ");
inputYear = keyboard.nextLine();
String stringYear = ""+ inputYear.charAt(inputYear.length()-2) + inputYear.charAt(inputYear.length()-1);
int year = Integer.parseInt(stringYear);
int intDay = Integer.parseInt(day);
switch(month)
{
// I tried to test my program by using my first case " January ", However it goes right through every case directly for my default case.
case "January || january" :
int janKey = 1;
int janQuarter = year / 4;
int janSum = year + janQuarter + intDay + janKey;
System.out.print( " Date Entered Was : " + month + ","+ day + "" + inputYear);
System.out.print( " Last Two Digits Of The Year Were : " + year);
System.out.print( " One Quarter Of Last Two Digits : " + janQuarter);
System.out.print( " The Given Day Of The Month Entered : " + day);
System.out.print( " The Index Key This Moth is : " + janKey);
System.out.print( " The Sum Of All The number Above is : " + janSum);
System.out.print( " \n \n The Day Of The Week Was : ");
int weekDay = dayLookUp(janSum);
System.out.print( " \n \n The Day Of The Week Was : " + weekDay);
break;
case "February || february":
int febKey = 4;
break;
case "March || march":
int marKey = 4;
break;
case "April || april":
int aprKey = 0;
break;
case "May || may":
int maykey = 2;
break;
case "June || june":
int junKey = 5;
break;
case "July || july":
int julKey = 0;
break;
case "August || august":
int augKey = 3;
break;
case "September || september":
int septKey = 6;
break;
case "October || october":
int octKey = 1;
break;
case "November || november":
int novKey = 4;
break;
case "December || december":
int decKey = 4;
break;
// IN MY DEFUALT CASE " inputValidation " WILL BE EXECUTED
default:
JOptionPane.showMessageDialog(null," Invalid Entry Please Try Again " );
}
}
public static int dayLookUp ( int janSum )
{
int sum = janSum;
int day = 14 % 7;
return day;
}
}
The way you're doing it now, it's looking for the whole string as is, literally, not interpreting the || as any form of or.
You can either set the element in the switch to uppercase or lowercase use :
switch(month.toLowerCase()) {
case "january" :
...
break;
case "february":
...
...
}
or you have to double case elements:
switch (month) {
case "January":
case "january":
...
break;
case "February":
case "february":
...
...
}
The mistake is at "January || january" this is one String use case "January": case "january":
You cannot test for alternatives this way, case "January || january": doesn't work. You can give alternatives with multiple cases
switch (month) {
case "january":
case "January":
int janKey = 1;
without an intervening break. This causes a fall through to the second case, when january is entered. The same is with the other months, of course.
I think it might be due the switch statement.
Do I have make the both them switch statements for them to work out.
import java.util.Scanner;
public class mylab
{
public static void main(String[] args)
{
Scanner in = new Scanner(System.in);
int month;
int day;
String season= "seasons";
System.out.print("type a two digit month");
System.out.print(" and day");
month = in.nextInt();
day = in.nextInt();
String winter = " winter ";
String summer = " summer";
String spring = " spring";
System.out.print(" Month="+ month +" Day= "+day);
switch (month) {
case 1:
month = 1; System.out.println(" Winter");
break;
case 2:
month = 2; System.out.println(" Winter");
break;
case 3:
month= 3;System.out.println(" Winter");
break;
case 4:
month= 4;System.out.println(" Spring");
break;
case 5:
month = 5;System.out.println(" Spring");
break;
case 6:
month = 6 ;System.out.println(" Spring");
break;
case 7:
month = 7 ;System.out.println(" Summer");
break;
case 8:
month = 8;System.out.println(" Summer");
break;
case 9:
month = 9;System.out.println(" Summer");
break;
case 10:
month = 10;System.out.println(" Fall");
break;
case 11:
month = 11;System.out.println(" Fall");
break;
case 12:
month = 12;System.out.println(" Fall");
break;
}
How , do I make this part work with the switch statement
the pseudo code for this portion is If month is divisible by 3 and day >= 21, If season is "Winter", season = "Spring",Else if season is "Spring", season = "Summer",Else if season is "Summer", season = "Fall"
Else season = "Winter"
if (month % 3 == 0 && day >= 21)
{
if ( season.equals(winter) )
System.out.println(" Spring");
else if ( season.equals(spring) )
System.out.println ( "Summer" );
else if ( season.equals(summer) )
System.out.println ( " fall");
else if ( season.equals(winter) )
System.out.println( " winter");
}
}
}
This is how I'd probably write it (if I absolutely had to keep the switch and I didn't care to check user input):
import java.util.Scanner;
public class mylab {
public static void main(String[] args) {
int month, day;
Scanner in = new Scanner(System.in);
System.out.print("Type a two digit month: ");
month = in.nextInt();
System.out.print("Type a two digit day: ");
day = in.nextInt();
System.out.print(" Month="+ month +" Day= "+day+" ");
if(month%3==0 && day>=21) {
month++;
if(month>12) month=1;
}
switch (month) {
case 1: case 2: case 3: System.out.println("Winter"); break;
case 4: case 5: case 6: System.out.println("Spring"); break;
case 7: case 8: case 9: System.out.println("Summer"); break;
case 10: case 11: case 12: System.out.println("Fall"); break;
}
}
}
i am making a program that reads in the month 1-12 and the start day, 1-7 for sunday, monday, etc. it prints the first week fine but im having problems printing the rest of the days after the first week. it wont format the output to have a space between the rest of the days, only the first day after the first week.
side note: Keyboard is a class i have included in my project
heres my code:
import java.io.*;
public class CalendarMonth
{
static final int WEEK = 7;
public static void main(String[] args) throws IOException
{
String proceed;
char repeatCheck;
int days;
String leapYear;
char leapYearCheck;
int startDay;
do
{
days = getDays();
System.out.println(days);
System.out.println("Please enter a number 1-7 that the month starts on: (1 for sunday, 2 for monday, etc)");
startDay = Keyboard.readInt();
while(startDay < 1 || startDay > 7)
{
System.out.println("You did not enter a number 1-7, Try again: ");
startDay = Keyboard.readInt();
}
System.out.println(" s m t w th f sa");
printMonth(days,startDay);
System.out.println("\nWould you like to print another month?");
proceed = Keyboard.readString();
repeatCheck = proceed.charAt(0);
}while(repeatCheck == 'y');
}
public static int getDays() throws IOException
{
int month;
String leapYear;
int startDay;
int days = 0;
char leapYearCheck;
System.out.println("Please input a number 1-12 to print the corresponding month: ");
month = Keyboard.readInt();
while (month < 1 || month > 12)
{
System.out.println("You did not put a number 1-12, Try again: ");
month = Keyboard.readInt();
}
switch(month)
{
case 1: days = 31;
break;
case 2:
System.out.println("is it a leap year? ");
leapYear = Keyboard.readString();
leapYearCheck = leapYear.charAt(0);
while(leapYearCheck != 'y' && leapYearCheck != 'n')
{
System.out.println("you did not enter a yes or no answer, is it a leap year?");
leapYear = Keyboard.readString();
leapYearCheck = leapYear.charAt(0);
}
if (leapYearCheck == 'y')
{
days= 29;
}
else
{
days = 28;
}
break;
case 3: days = 31;
break;
case 4: days = 30;
break;
case 5: days = 31;
break;
case 6: days = 30;
break;
case 7: days = 31;
break;
case 8: days = 31;
break;
case 9: days = 30;
break;
case 10: days = 31;
break;
case 11: days = 30;
break;
case 12: days = 31;
break;
}
return days;
}
public static void printMonth(int days, int startDay)
{
int count;
count = startDay;
for (int counter = 1; counter <= 7; counter++)
{
if (counter < startDay)
{
System.out.print(" ");
count = count-1;
}
else
{
System.out.printf("%2d", count);
count++;
}
}
//int restOfTheMonth = (WEEK - startDay);
System.out.println();
for(int restOfTheMonth = count; restOfTheMonth <= days; restOfTheMonth++)
{
if (restOfTheMonth%WEEK==0)
{
System.out.println();
}
System.out.printf("%2d", restOfTheMonth);
}
}
}