Question

我无法使用for循环在Java程序中打印以下模式。请寻求帮助。

代码

    Scanner sc = new Scanner(System.in); // Taking rows value from the user
    System.out.println("How many rows you want in this pattern?");
    int rows = sc.nextInt();
    System.out.println("Here is your pattern....!!!");
    for (int i = rows; i >= 1; i--) {
        for (int j = 1; j < i; j++) {
            System.out.print(" ");
        }
    }

Answer 1

尝试此代码，

public static void main(String args[]) throws Exception {
    try (Scanner sc = new Scanner(System.in);) { // Taking rows value from the user
        System.out.println("How many rows you want in this pattern?");
        int rows = sc.nextInt();
        if(rows <=0) {
            System.out.println("Please enter a positive number only.");
            return;
        }
        for (int i = 0; i < rows; i++) {
            for (int j = rows; j > 0; j--) {
                if (j <= i + 1) {
                    System.out.print(rows - j + 1);
                } else {
                    System.out.print(" ");
                }
            }
            System.out.println();
        }
    }
}

打印输入5，

您要使用此模式多少行？ 5

Answer 2

在您当前的代码中，您只是在打印空间。现在必须更进一步，并打印数字和新行。

您可以按照以下步骤进行操作。 See it working here：

public class PattrenClass 
{ 
    public static void main(String[] args) 
    { 
        //Connecting Keyboard to Scanner with `try-with-resources`
        try(Scanner sc = new Scanner(System.in);)
        {
            System.out.println("How many rows you want in this pattern?");
            int rows = sc.nextInt(); //Taking rows value from the user
            System.out.println("Here is your pattern....!!!");
            for (int i = rows; i > 0; i--)
            { 
                for (int j = 1; j < i; j++) 
                { 
                    System.out.print(" "); 
                }
                for (int j = rows; j >= i; j--) 
                { 
                    System.out.print(j); 
                }
                System.out.println(); 
            }
        }
    }
}

输出：

How many rows you want in this pattern?
5
Here is your pattern....!!!
    5
   54
  543
 5432
54321

如何在JAVA中使用嵌套的for循环打印以下模式？

2 个答案: