循环进阶经典练习题
案例一：输出1-100中被5整除的数，每行输出6个
package loopprc; public class loopdemo01 { //输出1-100中被5整除的数，每行输出6个 public static void main(String[] args) { int j=0; for (int i = 0; i <=100; i++) { if (i%5==0){ System.out.print(i+"\t"); j++; if (j%6==0){ System.out.println(); } } } } }
案例二：实现一个功能：
请录入10个int类型的数字，当你输入的数是666的时候，中断程序
判断其中录入的正数的个数并输出
判断系统的推出状态：是正常的推出还是被迫退出
Scanner sc = new Scanner(System.in); int count = 0; for (int i = 1; i <= 10; i++) { System.out.println("请输入第一个："+i+"数字"); int num = sc.nextInt(); if (num==666){ count = 1; break; }else { count = 2; } } if (count==1){ System.out.println("被迫退出"); }else { System.out.println("正常退出"); }
案例三：输出乘法口诀
public static void chengfa(){ for ( int j =1; j <=9; j++) { for (int i = 1; i <=j; i++) { System.out.print(i+" * "+j+" = "+(i*j)+" "); } System.out.println(); } }
第二种方法：
public static void chengfa(){ for ( int j =1; j <=9; j++) { for (int i = 1; i <=j; i++) { System.out.print(i+" * "+j+" = "+(i*j)+" "); } System.out.println(); } }
案例四：打印各种形状：
直角三角形：
public static void zhijiaosanjiao1(){ for (int i = 0; i <5; i++) { for (int j =0; j <i; j++) { System.out.print(" "+"*"); } System.out.println(" "); } } public static void zhijiaosanjiao(){ for (int i = 0; i <5; i++) { for (int j =5; j >i; j--) { System.out.print(" "+"*"); } System.out.println(" "); } }
等腰三角形：
public static void zhijiaosanjiao1(){ for (int i = 0; i <5; i++) { for (int j =0; j <i; j++) { System.out.print(" "+"*"); } System.out.println(" "); } } public static void zhijiaosanjiao(){ for (int i = 0; i <5; i++) { for (int j =5; j >i; j--) { System.out.print(" "+"*"); } System.out.println(" "); } }
等腰倒立三角形
public static void zhijiaosanjiao1(){ for (int i = 0; i <5; i++) { for (int j =0; j <i; j++) { System.out.print(" "+"*"); } System.out.println(" "); } } public static void zhijiaosanjiao(){ for (int i = 0; i <5; i++) { for (int j =5; j >i; j--) { System.out.print(" "+"*"); } System.out.println(" "); } }
菱形：
public static void zhijiaosanjiao1(){ for (int i = 0; i <5; i++) { for (int j =0; j <i; j++) { System.out.print(" "+"*"); } System.out.println(" "); } } public static void zhijiaosanjiao(){ for (int i = 0; i <5; i++) { for (int j =5; j >i; j--) { System.out.print(" "+"*"); } System.out.println(" "); } }
空心菱形：
public static void zhijiaosanjiao1(){ for (int i = 0; i <5; i++) { for (int j =0; j <i; j++) { System.out.print(" "+"*"); } System.out.println(" "); } } public static void zhijiaosanjiao(){ for (int i = 0; i <5; i++) { for (int j =5; j >i; j--) { System.out.print(" "+"*"); } System.out.println(" "); } }
输出空心的诀窍就是首尾输出。
