why I'm getting only one line of Q in output?

Question about the task

Filled rectangle

Java Syntax, Level 4, Lesson 3

Under discussion

is it compulsory to write int width in the first while loop and not in the starting if yes then why?

package en.codegym.task.pro.task04.task0404; /* Filled rectangle */ public class Solution { public static void main(String[] args) { //write your code here int height = 0; int width = 0; while (height < 5){ while (width < 10){ System.out.print("Q"); width++;} System.out.println(); height++;} } }

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Alex Buyanov

Level 47 , Netherlands

2 October 2022, 16:14

useful

The answer to your question is "no": it is not compulsory to put "width" initialization into the first (outer) loop. You problem is in the logic of your code. Try to analyze it step by step (maybe add "debug" prints next time). But let's walk through: 1) program starts 2) height is created (initialized) with value 0; width with value 0; 3) outer loop starts (iterating over height) 4) inner loop starts (iterating over width) 5) inner loop completes its job and prints "QQQQQQQQQQ" 6) now, height == 0, width == 10 7) outer loop prints empty line and increments height by 1 8) now, height == 1, width == 10 9) inner loop starts new iteration, but width == 10 so loop exits without single iteration 10) outer loop prints empty line and increments height by 1 11) now, height == 2, width == 10 ... And so on, until height == 5 and program is terminated. See the issue? Width is never reset back to zero. So there are two ways to fix it: a) move width initialization inside outer loop. Every iteration it will re-create width variable with a value of 0; b) If you like your variables initialized all in the same place (like you did), then set width = 0 after inner loop exits;

Thomas

Level 41 , Bayreuth, Germany

1 October 2022, 20:15

I wrote some debug code for you. Place it between line 12 and 13 and you'll see what's going on. It has to do with variable scopes.

System.out.format("Inner loops condition: %s, entering inner loops body: %s%n",  width < 10, width < 10 ? "yes" : "no");