part13 advanced cycle

Output a line

demand

• Use loops to complete
• Receive an integer from the keyboard
• Suppose the user enters a 6
• Then output 6 star flowers in one line
• 6

solve

• Code

import java.util.Scanner;

public class ppp {
    
    
    public static void main(String[] args) {
    
    

        // 固定的获得Scanner工具的写法
        // 类型名称 变量名 = 值;
        Scanner ipt = new Scanner(System.in);

        // 使用工具的功能,得到一个整数
        System.out.println("请输入内容：");
        int a = ipt.nextInt();
        System.out.println("从键盘接收到了一个整数，值为" + a);

        for (int i = 0; i < a; i++) {
    
    
            System.out.print("*");
        }

    }
}

Output multiple lines

demand

• Receive an integer from the keyboard
• If the user enters 2
• Then output two lines of content
• Each line of content is *****
  -a line of content composed of five stars

solve

• Code

import java.util.Scanner;

public class ppp {
    
    
    public static void main(String[] args) {
    
    

        // 获得键盘输入的工具
        Scanner ipt = new Scanner(System.in);

        // 使用工具的方法
        System.out.println("请问需要打印几行：");
        int num = ipt.nextInt();

        for (int i = 0; i < num; i++) {
    
    
            // 需要重复做的内容
            System.out.println("*****");
        }

    }
}

Output a rectangle

demand

• Receive an integer from the keyboard
• If the user enters 3
• Then output three lines of content
• Each row is composed of three*

solve

• Code

  import java.util.Scanner;
  
  public class ppp {
  
  
      public static void main(String[] args) {
  
          // 代码简化，输出矩形
          int num = 4;
  
  
          for (int j = 0; j < num; j++) {
              // 输出一行星花，由三个符号组号
              for (int i = 0; i < num; i++) {
                  System.out.print("*");
              }
              System.out.println();
  
          }
  
  
      }
  
  
  }
  
  

Output a triangle

demand

• Receive an integer from the keyboard
• If the user enters 4
• Output four rows of triangles
• One symbol on the first line
• Two symbols on the second line
• 。。。。

solve

• Code

  import java.util.Scanner;
  
  public class ppp {
  
      public static void main(String[] args) {
  
          // 用户输入数字5，打印五行的三角形
          int num = 6;
  
          // 行循环
          for(int j=1;j<=num;j++){
              for (int i = 0; i < j; i++) {
                  System.out.print("*");
              }
              System.out.println();
          }
  
  
  
  
      }
  
  
  }
  
  

Output ninety-nine multiplication table

demand

• Output ninety-nine multiplication table

solve

• Code

import java.util.Scanner;

public class ppp {
    
    

    public static void main(String[] args) {
    
    
        // 行循环，一共需要输出九行，所以从1开始一直到9
        for (int hang=1;hang<=9;hang++){
    
    
            // 每一行的内容输出循环，当前行需要输出几次内容，由当前的hang行号决定
            for(int lie=1;lie<=hang;lie++){
    
    
                System.out.print(lie+"x"+hang+"="+hang*lie+"\t");
//                System.out.print("*");
            }
            System.out.println();
        }


    }


}