问题
I am a Senior High School student and I'm having a hard time how to add a white spaces in the first row of my calendar using nested loops. We can't use arrays becauce we haven't learned about it yet(it is our next topic).
Our teacher asked us to create a 2020 calendar using nested loops in java. The user need to enter a month using a numerical value (1-12). and we need to display the corresponding calendar for the year 2020 of the entered month.
Here is my code as of now:
Scanner s = new Scanner(System.in);
System.out.println("Enter month[1-12]");
int month = s.nextInt();
System.out.println("Sun\tMon\tTues\tWed\tThur\tFri\tSat");
switch(month)
{
case 1: //1 stands for the month of January 2020
for(int i = 1; i <= 31; i++)
{
System.out.print(i+ "\t");
if(i%7 == 0)
{
System.out.println();
}
}
}
This is the current output of my codes:
Sun Mon Tue Wed Thu Fri Sat
1 2 3 4 5 6 7
8 9 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
29 30 31
This the needed sample output on our program in January 2020:
January 2020
Sun Mon Tue Wed Thu Fri Sat
1 2 3 4
5 6 7 8 9 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30 31
EDITED: And this is the sample output on our program in the month of February
February 2020
Sun Mon Tue Wed Thu Fri Sat
1
2 3 4 5 6 7 8
9 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28 29
Any idea to get there please?
回答1:
You can do like this
public static void main(String[] args) throws IOException {
int sumDay = 0;
Scanner in = new Scanner(System.in);
System.out.print("Please enter the year：");
int year = in.nextInt();
System.out.print("Please enter month：");
int month = in.nextInt();
System.out.println(year + "year" + month + "month：");
for (int i = 1900; i < year; i++) {
if ((i % 4 == 0) && (i % 100 != 0) || (i % 400 == 0)) {
sumDay += 366;
} else {
sumDay += 365;
}
}
for (int j = 1; j < month; j++) {
if (j == 4 || j == 6 || j == 9 || j == 11) {
sumDay += 30;
} else if (j == 2) {
if ((year % 4 == 0) && (year % 100 != 0) || (year % 400 == 0)) {
sumDay += 29;
} else {
sumDay += 28;
}
} else {
sumDay += 31;
}
}
/*The above code calculates the total number of days from January 1, 1900 to the entered year and month. If 2020 and 10 are entered, the number of days from 1900.1.1 to 2020.9.30 will be calculated*/
/*xingQi is used to calculate the day of the week on the 1st of the entered month*/
int xingQi = (sumDay + 1) % 7;
int everydayXingQi = sumDay + 1;
/*monthDay is used to receive the days of the month*/
int monthDay;
System.out.println("Sun\tMon\tTue\tWed\tThu\tFri\tSat");
if (month == 4 || month == 6 || month == 9 || month == 11) {
monthDay = 30;
} else if (month == 2) {
if ((year % 4 == 0) && (year % 100 != 0) || (year % 400 == 0)) {
monthDay = 29;
} else {
monthDay = 28;
}
} else {
monthDay = 31;
}
/*Output the space before the 1st of each month*/
for (int i = 0; i < xingQi; i++) {
System.out.print("\t");
}
/*Output the number of days in each month and control line break*/
for (int i = 1; i <= monthDay; i++) {
if (everydayXingQi % 7 == 6) {
System.out.print(i + "\n");
} else {
System.out.print(i + "\t");
}
everydayXingQi++;
}
}
回答2:
you need to add some spaces according to days of a month:
int year = 2020;
int startDayofYear = 3; // Wednesday is the start day of 2020
int dayCounter = startDayofYear;
int nbrOfDays = 0;
String monthName = "";
for (int month = 1; month <= 12; month++) {
// Switch to chose the month
switch (month) {
case 1:
monthName = "January";
nbrOfDays = 31;
break;
case 2:
monthName = "February";
if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) {
nbrOfDays = 29;
break;
} else {
nbrOfDays = 28;
break;
}
case 3:
monthName = "March";
nbrOfDays = 31;
break;
case 4:
monthName = "April";
nbrOfDays = 30;
break;
case 5:
monthName = "May";
nbrOfDays = 31;
break;
case 6:
monthName = "June";
nbrOfDays = 30;
break;
case 7:
monthName = "July";
nbrOfDays = 31;
break;
case 8:
monthName = "August";
nbrOfDays = 31;
break;
case 9:
monthName = "September";
nbrOfDays = 30;
break;
case 10:
monthName = "October";
nbrOfDays = 31;
break;
case 11:
monthName = "November";
nbrOfDays = 30;
break;
case 12:
monthName = "December";
nbrOfDays = 31;
break;
}
System.out.printf("%15s %d \n", monthName, year);
System.out.println("----------------------------");
System.out.printf("%s %s %s %s %s %s %s\n ", "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat");
for (int space = 1; space <= startDayofYear; space++) {
System.out.printf("%4s", " ");
}
for (int i = 1; i <= nbrOfDays; i++) {
dayCounter++;
if (dayCounter % 7 == 0)
System.out.printf("%- 4d\n", i);
else
System.out.printf("%-4d", i);
}
startDayofYear = (startDayofYear + nbrOfDays) % 7;
System.out.println();
}
来源：https://stackoverflow.com/questions/64763790/calendar-in-a-nested-loop-using-java