一些练习代码

• 奇偶数
• 考试奖励
• 春夏秋冬
• 顺序输出1-5,5-1
• 求和1-5
• 求偶数和(100内)
• 水仙花数
• 缝七必过

	public static void main(String[] args) {
		Scanner n = new Scanner(System.in);
		//键盘输入一个数字
		System.out.print(" Please enter a number ：");
		int a = n.nextInt();
		if (a%2!=0) {//取余不等于0则为基数
			System.out.print("Cardinal number");
		}else {// 取余为0则为偶数
			System.out.print("even numbers");
		}
	}
	

	public static void main(String[] args) {
	Scanner n = new Scanner(System.in);
	int  grades = n.nextInt(); 
	if (grades>=94 && grades<=100) {
		System.out.print("奖励A");
	}else if(grades>=90 && grades<=94){
		System.out.print("奖励B");
	}else if(grades >=80 && grades <= 89) {
		System.out.print("奖励C");
	}else {
		System.out.print("没有奖励");
		}
	}

• 示例1

	public static void main(String[] args) {
	Scanner month = new Scanner(System.in);
	System.out.print("Please enter a month：");
	int  Month = month.nextInt(); //键盘输入月份
	switch(Month){
	case 1:System.out.print("It's spring");break;
	case 2:System.out.print("It's Spring");break;
	case 3:System.out.print("It's Spring");break;
	case 4:System.out.print("It's summer");break;
	case 5:System.out.print("It's summer");break;
	case 6:System.out.print("It's summer");break;
	case 7:System.out.print("It's autumn");break;
	case 8:System.out.print("It's autumn");break;
	case 9:System.out.print("It's autumn");break;
	case 10:System.out.print("It's winter");break;
	case 11:System.out.print("It's winter");break;
	case 12:System.out.print("It's winter");break;
		}
	}	

• 示例2

	public static void main(String[] args) {
	Scanner month = new Scanner(System.in);
	System.out.print("Please enter a month：");
	int  Month = month.nextInt(); //键盘输入月份
	switch(Month){
	case 1:
	case 2:
	case 3:
		System.out.print("It's Spring");break;
	case 4:
	case 5:
	case 6:
		System.out.print("It's summer");break;
	case 7:
	case 8:
	case 9:
		System.out.print("It's autumn");break;
	case 10:
	case 11:
	case 12:
		System.out.print("It's winter");break;
		}
	}

	public static void main(String[] args) {
		int i;
		for(i=1;i<6;i++) {
			System.out.println(i);
		}
		for(i=6;i>0;i--) {
			System.out.println(i);
		}
	}

	public static void main(String[] args) {
		int sum=0;
		for(int i=1;i<=5;i++) {
		sum += i;
		}
		System.out.println(sum);
	}

	public static void main(String[] args) {
		int sum=0;
		for(int i=1;i<=100;i++) {
		 if(i%2==0) {
			 sum += i;
		 }
	 	}
	 System.out.print(sum);
	}

• 示例1

	public static void main(String[] args) {
		for(int i=100;i<10000;i++) {
			int ge = i%10;
			int shi = i/10%10;// 获取每个数字
			int bai = i/10/10%10;
			if (ge*ge*ge+shi*shi*shi+bai*bai*bai ==1) {
				System.out.println(i);//判断是否属于水仙花数
			}
		}
	}

• 示例2

	public static void main(String[] args) {
		int count=0;
		for(int i=100;i<10000;i++) {
			int ge = i%10;
			int shi = i/10%10;// 获取每个数字
			int bai = i/10/10%10;
			if (ge*ge*ge+shi*shi*shi+bai*bai*bai ==1) {
				System.out.println(i);//判断是否属于水仙花数
				count++;//计数
			}
		}
		System.out.print("有"+count+"个");
	}

    public static void main(String[] args) {
        getSeven();//缝七必过
    }
    //遇见7 或者是含有7或者是7的倍数则跳过
    public static void getSeven() {
        int a, b, c;
        for (int i = 1; i < 100; i++) {
            a = i % 10;
            b = i / 10 % 10;
            c = i % 7;
            if (a == 7 || b == 7 || c == 0) {
                System.out.println(i);
            }
        }
    }