一、不使用各种花里胡哨
package net.dc.algchallenge;
import java.util.Scanner;
import java.util.Arrays;
public class JudgeDays {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
final int[] SPECIFICMONTH$1 = {
31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};//为平年时，每月的天数
final int[] SPECIFICMONTH$2 = {
31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};//为闰年时，每月的天数
final Integer[] MONTH31 = {
1, 3, 5, 7, 8, 10, 12};//天数为31的各月
final Integer[] MONTH30 = {
4, 6, 9, 11};//天数为30的各月
while (true) {
//声明部分：
boolean isLeapYear, isMatch = false;
int specificDays = 0;//具体为一年中多少天
//输入部分:
System.out.print("year = ");
int year = sc.nextInt();
System.out.print("month = ");
int month = sc.nextInt();
System.out.print("day = ");
int day = sc.nextInt();
//判断是否为闰年:
isLeapYear = (year % 4 == 0 && !(year % 100 == 0)) || (year % 400 == 0) || (year % 3200 == 0 && year % 172800 == 0);
//判断输入的月份及其天数是否匹配:
if (Arrays.asList(MONTH31).contains(month) && (day >= 1 && day <= 31)) {
isMatch = true;
} else if (Arrays.asList(MONTH30).contains(month) && (day >= 1 && day <= 30)) {
isMatch = true;
} else if (!isLeapYear && month == 2 && (day >= 1 && day <= 28)) {
isMatch = true;
} else if (isLeapYear && month == 2 && (day >= 1 && day <= 29)) {
isMatch = true;
}
//输出部分:
if (isMatch) {
if (!isLeapYear) {
for (int i = 0; i < month - 1; i++) {
specificDays += SPECIFICMONTH$1[i];
}
specificDays += day;
System.out.println(String.format("该日期为其年的第%d天", specificDays));
} else {
for (int i = 0; i < month - 1; i++) {
specificDays += SPECIFICMONTH$2[i];
}
specificDays += day;
System.out.println(String.format("该日期为其年的第%d天", specificDays));
}
} else {
System.out.println("\033[31m请输入正确的日期！\033[0m");
}
}
}
}
实现效果：
二、简易版本
package net.dc.lesson20.exercise;
import java.util.Calendar;
import java.util.Scanner;
public class GetDays {
public static void main(String[] args) {
//获取Calendar实例并实现输入
Calendar calendar = Calendar.getInstance();
Scanner sc = new Scanner(System.in);
//输入年月日
System.out.print("year = ");
int year = sc.nextInt();
System.out.print("month = ");
int month = sc.nextInt();
System.out.print("day = ");
int day = sc.nextInt();
if (month >= 1 && month <= 12) {
//定义currentDays变量记录当前天数
int currentDays = 0;
for (int i = 1; i < month; i++) {
//把当前月份的天数设置为0，就可以得到上个月的完整天数
calendar.set(year, i, 0);
currentDays += calendar.get(Calendar.DATE);
}
//最后加上本月的天数
currentDays += day;
System.out.println(year + "年" + month + "月" + day + "日是该年的第" + currentDays + "天");
} else {
System.out.println("\033[31m请输入正确的时间！\033[0m");
}
}
}
实现效果：
