如何在java中仅使用while循环打印带星号的正方形？

我想知道如何在java中打印一个只有while循环的带星号的正方形 但是没有out for循环，没有任何逻辑操作，比如：和或

这段代码应该是这样的：如果我们输入4，它应该打印：

* * * *
*     *
*     *
* * * * 

但它还做了其他一些事情，比如：

* **


*  

---

您可以注意到，必须仅在边框值上打印星号。也就是说，当x或y为0或x或y等于平方边-1时

for (int x=0; x < squareside; ++x) {
    for (int y=0; y < squareside; ++y)
        if (x == 0 || x+1 == squareside ||
            y == 0 || y+1 == squareside) {
            System.out.print("*");
        } else {
            System.out.print(" ");
        }
    System.out.println();
}

---

快速和冗长，但应该工作。除了while循环之外，它不使用if或其他任何东西。请随意优化：

public static void main(String... args) {
    // logic :
    // print first line * * * *
    // print the rest of lines *      * in a loop
    // print last line * * * *

    int len = 5; // user input
    int x = 0;

    // print first line
    while (x++ < len) {
        System.out.print("* ");
    }
    System.out.println(); // new line
    // print the rest of lines *      * in a loop
    x = 0;
    while (x++ < len - 2) {
        System.out.print('*'); // beginning of line
        int y = 0;
        while (y++ < len - 2) {
            System.out.print("  "); // dobule spaces
        }
        System.out.println(" *"); // end of line
    }
    x = 0;
    // print the last line
    while (x++ < len) {
        System.out.print("* ");
    }
}

---

这是解决这个问题的简单方法。如果需要，可以在星号之间轻松添加空格：

   // Square.java
   // Create a hollow square of asterisks.
   // The side size is entered by the user 
   import java.util.Scanner;

   public class Square
   {
     public static void main(String[] args)
     {
        int row = 1;
        int column = 1;
        int side;

        Scanner input = new Scanner(System.in);

        System.out.println("Please enter the size of the square side: ");
        side = input.nextInt();

        while (row <= side)
        {
            column = 1;
            System.out.print("*");
            while (column <= (side - 2))
            {
                System.out.print(row == 1 || row == side ? "*" : " ");
                ++column;
            }
            ++row;
            System.out.printf("*%n");
        }
     }
  }

---

对于for循环，没有什么比while循环更有效的了。对于int x=0；xintx=0；当ximport java.util.Scanner; public class Main { public static void main(String[] args) { System.out.print("Enter the size of the side of a square: "); Scanner input = new Scanner(System.in); int num = input.nextInt(); String re1 = repeat1("*", num); String re2 = repeat2("*", num); System.out.println(re1); System.out.print(re2); System.out.print(re1); } public static String spaces(int i) //Repeat space { String spaces = ""; for (int j = 1; j <= (2 * i - 3); j++) //(2 * i - 3) : for exrta space between Asterisks on Top and bottom side { spaces = spaces + " "; } return spaces; } public static String repeat1(String s, int i) //Top and bottom side { String tst = ""; for (int j = 1; j <= i; j++) { tst = s + " " + tst; } return tst; } public static String repeat2(String s, int i) // Left and right side { spaces(i); String tst1 = ""; for (int j = 1; j <= i - 2; j++) { tst1 = s + spaces(i) + s + "\n" + tst1; } return tst1; } }

   // Square.java
   // Create a hollow square of asterisks.
   // The side size is entered by the user 
   import java.util.Scanner;

   public class Square
   {
     public static void main(String[] args)
     {
        int row = 1;
        int column = 1;
        int side;

        Scanner input = new Scanner(System.in);

        System.out.println("Please enter the size of the square side: ");
        side = input.nextInt();

        while (row <= side)
        {
            column = 1;
            System.out.print("*");
            while (column <= (side - 2))
            {
                System.out.print(row == 1 || row == side ? "*" : " ");
                ++column;
            }
            ++row;
            System.out.printf("*%n");
        }
     }
  }