2021-3-27 Java第五章while循环结构的运用及练习

待我称王封你为后i 2022-11-14 00:47 40阅读 0赞

//第五章 5.2 while循环结构
    	Scanner input= new Scanner(System.in);
    	 long i4=1;
    	 while(i4<=50) { 
    		 System.out.println("打印第"+i4+"份试卷");
    
    
    
    		 i4++;
    	 }
    	 System.out.println("\n");
    	 
    	 
    	 //课堂练习：输出1-100数字
    	 int p = 1;
    	 while(p<=100) { 
    		 System.out.println(p);
    		 p++;
    	 }
    	 System.out.println("\n");
    	 
    	 
    	 //打印100以内的偶数
    	 int s = 1;
    	 while(s<=100) { 
    		 if(s%2==0)
    		 System.out.println(s);
    		 s=s+1;
    	 }
    	 System.out.println("\n");
    	 
    	 
    	 //100以内偶数的和
    	 int e = 1;
    	 int sum4 = 0;
    	 while(e<=100) { 
    		 if(e%2==0)
    		 System.out.println(e);
    		 sum4+=e;
    		 e=e+2;
    	 }
    	 System.out.println("100以内偶数的和为："+sum4);	
    	 
    	 		//第五章 5.4循环结构 do-while语句
    	 		System.out.println("合格了吗？(y/n)");
    	 		String out = input.next();
    	 		while("n".equals(out)) { 
    	 			System.out.println("上午阅读教材\n"+"下午上机编码");
    	 			System.out.println("合格了吗？(y/n)");
    	 			out = input.next();
    	 			if(out.equals("y")) { 
    	 				System.out.println("完成学习任务");
    	 			}else { 
    	 				System.out.println("请输入(y/n,输入其他报错)");
    	 			}
    	 		}
    	 		System.out.println("请输入(y/n,输入其他报错)");
    	 		System.out.println("\n");
    	 		
    	 		
    	 		String she = "";
    	 		do{ 
    	 			System.out.println("上午阅读教材\n"+"下午上机编码");
    	 			System.out.println("合格了吗？(y/n)");
    	 			she = input.next();
    	 		}while(!"y".equals(she)); 
    	 		 System.out.println("完成任务");	
    	 		 System.out.println("\n");
    	 		 
    	 		 //100以内偶数的和
    	 		 int sum1 = 0;
    	 		 int i3 = 2;
    	 		 while(i3<=100) { 
    	 			 System.out.println(sum1);
    	 			 sum1+=i3;
    	 			 i3=i3+2;
    	 		 }
    	 		 System.out.println("\n100以内偶数的和:"+sum1);
    	 		System.out.println("\n");
    	 		
    	 		//求五门成绩的平均数
    	 		int i2 =1;
    	 		int sum2 = 0;
    	 		int yu = 0;
    	 		while(i2<=5) { 
    	 			System.out.println("请输入第"+i2+"门课");
    	 			sum2 = input.nextInt();
    	 			i2++;
    	 			yu+=sum2/5;
    	 		}
    	 		System.out.println("五门成绩的平均数为:"+yu);	
    	 		System.out.println("\n");
    	 		
    	 		//以及boolean在while和if中的练习
    	 		int i1 =1;
    	 		int avg = 0;
    	 		boolean iscon = false;
    	 		int score = 0;
    	 		int sum3 = 0;
    	 		while(i1<=3) { 
    	 			System.out.println("请输入第"+i1+"门课");
    	 			score = input.nextInt();
    	 			i1++;
    	 			sum3+=score;
    	 			if(score<0) { 
    	 				iscon = true;
    	 				break;
    	 			}
    	 		}
    	 		if(iscon) { 
    	 			System.out.println("输入有误，结束运行");
    	 		}else { 
    	 			avg = sum3/3;
    	 			System.out.println("三门课的平均成绩为:"+avg);
    	 		}
    	 		System.out.println("\n");		
    	 	}
    }

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