Creating a box in Java from user inputs, but how do I replace the interior of the box with a differe-CodePudding

I need to create a box using user inputs. My inputs are the dimensions (height x width), the "interior" (the character that the box is filled with), and the "border" (the character surrounding the interior). I'm almost done, I believe; I can assemble the box given the dimensions and border, but I'm struggling to figure out how to fill the inside.

I don't know how to use decision statements to determine which characters belong on which line. If the current line is the first line, I want to print only border characters, or if the current character on the line is the first character in that line, print a border character, but print the interior for the following characters (until the end char), etc.

My code:

// Below this comment: import the Scanner
import java.util.Scanner;
public class Box {
   public static void main(String[] args) {
      // Below this comment: declare and instantiate a Scanner
      Scanner scnr = new Scanner(System.in);

      // Below this comment: declare any other variables you may need
      int width;
      int height;
      char border;
      char interior;


      // Below this comment: collect the required inputs
      System.out.println("Enter width    : ");
      width = scnr.nextInt();
      System.out.println("Enter height   : ");
      height = scnr.nextInt();
      System.out.println("Enter border   : ");
      border = scnr.next().charAt(0);
      System.out.print("Enter interior : ");
      interior = scnr.next().charAt(0);


      // Below this comment: display the required results

      for (int j = 0; j < height; j  ) {
         for (int i = 1; i < width; i  ) {
            System.out.print(border);
         }
         System.out.print(border);
         System.out.println("");
      }
   }
}

As an arbitrary example, running my code with 7x5 dimensions and X and O characters gives me:

XXXXXXX
XXXXXXX
XXXXXXX
XXXXXXX

But my desired result would be:

XXXXXXX
XOOOOOX
XOOOOOX
XOOOOOX
XXXXXXX

CodePudding user response：

You can certainly use if-else control structures to do this, but a simpler option would be to create the inner box with 2 rows and 2 columns fewer than the given dimensions, and then append the borders. You didn’t say what the expectation is for boxes of 1 or 2 rows only, so, you’ll have to handle those cases as well.

Also, for testability purposes, I’d create a method that accepts the dimensions as integers, and returns the box. You can then print the box in the main method. You can even take it one step further and create one method to create the inner box, and another to pad it with borders. Basically, try not to shove your entire project into one main method.

CodePudding user response：

Change:

for (int j = 0; j < height; j  ) {
  for (int i = 1; i < width; i  ) {
    System.out.print(border);
  }
  System.out.print(border);
  System.out.println("");
}

To:

for (int j = 0; j < height; j  ) {
  for (int i = 1; i <= width; i  ) {
    if (j==0 || j==(height-1)) {
      System.out.print(border);
    }
    else {
      if (i==1 || i==width) {
        System.out.print(border);
      }
      else {
        System.out.print(interior);
      }  
    }
  }
  System.out.println();
}

This could obviously be written in many different ways, some much more compact than this. I think this way is easy to understand, though...

For instance, here's a shorter version that works, but is harder to interpret:

for (int j = 0; j < height; j  ) {
  for (int i = 1; i <= width; i  ) {
    System.out.print(((j==0 || j==(height-1)) || (i==1 || i==width)) ? border : interior);
  }
  System.out.println();
}