Java循环中初始化i了，但还是不能进行循环

Question

问题遇到的现象和发生背景

用代码块功能插入代码，请勿粘贴截图

package assignment;
import java.util.Scanner;

public class PrintCalendar {
    public static void main (String args[]) {
        Scanner in = new Scanner (System.in);
        int year = in.nextInt();
        int month = in.nextInt();
        int sum = 0 , k = 0 ;
        for(int i = 1 ; i < month - 1 ; i ++) {
            if(i == 2) {
                if(year % 4 == 0 && year % 100 != 0 || year % 400 == 0 ) {
                    sum =sum + 29;
                }
                else {
                    sum = sum+28;
                }
            }
            else {
                if(i == 4|| i == 6 || i == 9 || i == 11) {
                    sum = sum + 30;
                }
                else {
                    sum = sum + 31;
                }
            }
        }
        for(int a = 1900 ; a<= year -1 ; a ++) {
            if(a%4 == 0 && a%100 != 0 || a%400 == 0) {
                sum = sum + 356;
            }
            else {
                sum = sum + 365;
            }
        }
        sum = sum +1 ;
        int wekday = sum % 7 ;
        System.out.println("Mon\tTue\tWed\tThu\tFri\tSat\tSun");
        for(int j = 1 ; j <= wekday ; j ++) {
            System.out.println("\t");
        }
        if(year % 4== 0 && year % 100 != 0 || year % 400 == 0) {
            if(month == 2) {
                k = 29;
            }
            else if (month == 4 || month == 6 || month == 9 || month == 11) {
                k = 30;
            }
            else {
                k = 31;
            }
        }
        else {
            if(month == 2) {
                k = 28;
            }
            else if(month == 4 || month == 6 || month == 9 || month == 11) {
                k = 30 ;
            }
            else {
                 k = 31;
            }
        }
        for(int i = 1 ; i <=k ; i++);
        {
            if(sum % 7 == 6) {
                System.out.print(i+"\n");
            }
            else {
                System.out.print(i + ' ');
            }
        }
        System.out.println("\n");
    }
}

运行结果及报错内容

我想要达到的结果

循环正常进行

Answer 1

帮你的代码修改了下，是因为你的应该是67行代码里的i不是全局变量，所以用不了报错！

package cn.bdqn.demo13;
import java.util.Scanner;
public class PrintCalendar {
    public static void main (String args[]) {
        Scanner in = new Scanner (System.in);
        int year = in.nextInt();
        int month = in.nextInt();
        int sum = 0 , k = 0 ;
        for(int i = 1 ; i < month - 1 ; i ++) {
            if(i == 2) {
                if(year % 4 == 0 && year % 100 != 0 || year % 400 == 0 ) {
                    sum =sum + 29;
                }
                else {
                    sum = sum+28;
                }
            }
            else {
                if(i == 4|| i == 6 || i == 9 || i == 11) {
                    sum = sum + 30;
                }
                else {
                    sum = sum + 31;
                }
            }
        }
        for(int a = 1900 ; a<= year -1 ; a ++) {
            if(a%4 == 0 && a%100 != 0 || a%400 == 0) {
                sum = sum + 356;
            }
            else {
                sum = sum + 365;
            }
        }
        sum = sum +1 ;
        int wekday = sum % 7 ;
        System.out.println("Mon\tTue\tWed\tThu\tFri\tSat\tSun");
        for(int j = 1 ; j <= wekday ; j ++) {
            System.out.println("\t");
        }
        if(year % 4== 0 && year % 100 != 0 || year % 400 == 0) {
            if(month == 2) {
                k = 29;
            }
            else if (month == 4 || month == 6 || month == 9 || month == 11) {
                k = 30;
            }
            else {
                k = 31;
            }
        }
        else {
            if(month == 2) {
                k = 28;
            }
            else if(month == 4 || month == 6 || month == 9 || month == 11) {
                k = 30 ;
            }
            else {
                 k = 31;
            }
        }
        int i;
        for(i = 1 ; i <=k ; i++);
        {
            if(sum % 7 == 6) {
                System.out.print(i+"\n");
            }
            else {
                System.out.print(i + ' ');
            }
        }
        System.out.println("\n");
    }
}