Thread: Spaces at the start of every other line in a for loop

I'm attempting to get spaces at the beginning of every other line of the output of this program:

import java.util.Scanner;
public class Checkerboard
{
public static void main(String[] args)
{
int num;

Scanner input = new Scanner(System.in);

System.out.println ("What is the integer?");
num = input.nextInt();

for (int x = 0; x < num; x++)
{
for (int y = 0; y < num; y++)
{
System.out.print("A ");
}
System.out.println(" ");
}
}
}

The output of this program, if the user enters "4" for example, is:
A A A A A
A A A A A
A A A A A
A A A A A

I'm trying to get it to look like this:
A A A A A
(space)A A A A A
A A A A A
(space) A A A A A

Read the announcement to format correctly, but what you're doing wrong is printing the A's one by one, it seems the A's aren't affected by the input so you can print a whole line by itself. Here's what I came up with real quick, didn't test it but I think it works.

import java.util.Scanner;
public class Checkerboard{
 
	public static void main(String[] args){
		int num;
		Scanner input = new Scanner(System.in);
		System.out.println ("What is the integer?");
		num = input.nextInt();
 
		for (int x = 0; x < num/2; x++){
			System.out.println("A A A A A");
			for (int y = 0; y < num; y++){
				System.out.print(" ");
			}
			System.out.println("A A A A A");
		}		
	}
 
}

I'd have to agree with the above poster.

Originally Posted by Junky

I'd have to disagree with both above posters!

It appears that the space needs to be displayed on every even numbered line. Use the mod operator to work out if the current line is odd or even.

That code does apply the number of spaces on every other line. so it should work out to be the same. The code prints out the first set of lines while going to a new line. Then the spaces are added in the inner nested loop without going to a new line, after the spaces are added the line then prints again while going to a new line, therefore each loop pass prints out 2 lines of output. The one without spaces and one with spaces.

Originally Posted by Junky

But your advice to hard code it to print five A chars is just plain wrong!

May I ask why? It's probably not the best way to do it but it works.

Originally Posted by Junky

Because the whole point of the program is that the user can enter how many lines (and chars per line) they want displayed. That is what the num variable is for. If I enter 10 I should get 10 lines with 10 A's on each line. Your code cannot do that!

Not at all, because the input was 4 and there's 5 A's. No where did it specify that you need the amount of A's from the input. The number input was simply for the amount of spaces and lines of A's, 4 spaces were put in front of every other line and 4 lines were produced from the code. If it was the number 10, now there are 10 spaces and 10 lines of A's but if the case was that you needed 10 A's also then that's different but this didn't specify that.

Originally Posted by Junky

In the original post they probably made a mistake but if you look at the code both inner and outer loops iterate num number of times. So output is determined by the value the user inputs.

Yes but his code wasn't correct to begin with, from what the output proves that code is fine. Until the output is set to something else then that code is wrong. You're assuming that he wants it to print the number of A's also but the original post never said that. Now you're assuming the original post made a mistake.

Thanks for the replies everyone. I'd like to point out that Junky is correct! I made a typing error with the 5x5 output of A's. If the user enters 4 it will output 4x4.