4.16
1.输出3行6列的星号
package com.ym.practise; public class A1 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub for (int i = 1; i <= 3; i++) { for (int j = 1; j <= 6; j++) { System.out.print("*"); } System.out.println(); } } }
2.输出
*
**
***
****
*****
package com.ym.practise; public class A2 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub for (int i = 1; i <= 5; i++) { for (int j = 1; j <= i; j++) { System.out.print("*"); } System.out.println(); } } }
3.输出九九乘法表
package com.ym.practise; public class A3 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub for (int i = 1; i <= 9; i++) { for (int j = 1; j <= i; j++) { System.out.print(i + "*" + j + "=" + i * j + "\t"); } System.out.println(); } } }
4.输出
1
12
123
1234
12345
123456
1234567
12345678
123456789
package com.ym.practise; public class A4 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub for (int i = 1; i <= 9; i++) { for (int j = 1; j <= i; j++) { System.out.print(j); } System.out.println(); } } }
5.输出
1
22
333
4444
55555
666666
7777777
88888888
999999999
package com.ym.practise; public class A5 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub for (int i = 1; i <= 9; i++) { for (int j = 1; j <= i; j++) { System.out.print(i); } System.out.println(); } } }
6.输入年月日,并输出该日是该年的第几天
package com.ym.practise; import java.util.Scanner; public class A6 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Scanner input = new Scanner(System.in); System.out.println("输入年,月,日"); int y = input.nextInt(); int m = input.nextInt(); int d = input.nextInt(); int days = 0; for (int i = 1; i < m; i++) { switch (i) { case 4: case 6: case 9: case 11: days += 30; break; case 2: if (y % 4 == 0 && y % 100 != 0 || y % 400 == 0) { days += 29; } else { days += 28; break; } default: days += 31; } } days += d; System.out.println("是第" + days + "天"); } }
7.输入5个数,输出最大值(循环)
package com.ym.practise; import java.util.Scanner; public class A7 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Scanner input = new Scanner(System.in); System.out.println("输入5个数"); int a = 0; int max = 0; for (int i = 0; i < 5; i++) { a = input.nextInt(); if (i == 0) { max = a; } if (max < a) { max = a; } } System.out.println("最大值是" + max); } }
8.输入学生姓名,当输入Q时程序结束
package com.ym.practise; import java.util.Scanner; public class A8 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Scanner input = new Scanner(System.in); System.out.println("输入学生姓名"); String name = input.next(); while (!name.equals("Q")) { name = input.next(); } System.out.println("程序结束"); } }
9.输入一个数,判断是不是质数(只能被1和自身整除的数是质数)
package com.ym.practise; import java.util.Scanner; public class A9 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Scanner input = new Scanner(System.in); int a = input.nextInt(); boolean f = true; for (int i = 2; i < a; i++) { if (a % i == 0) { f = false; break; } } if (f) { System.out.println("是质数"); } else { System.out.println("不是质数"); } } }