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JavaScript

Posted by Dani Ivanov
Dani Ivanov
10,732 Points

Create a chess board with hashtags

Hello,

I have a JS exercise and it is to create a chess board using hashtags (#). After trying to solve it myself I gave in and looked at the proper code from the answers page.

Here it is 

var size = 8;

var board = "";

for (var y = 0; y < size; y++) {
  for (var x = 0; x < size; x++) {
    if ((x + y) % 2 == 0)
      board += " ";
    else
      board += "#";
  }
  board += "\n";
}
console.log(board);

And here is a screenshot of the output. http://www.evernote.com/shard/s264/sh/1242047c-af85-4762-a43f-2338675c318b/0e53aa00615541295cbe2f3a879992c9

Can somebody explain the logic behind this code and how it works. (also perhaps some alternative ways to solving the same problem)

1 Answer

Petros Sordinas
Petros Sordinas
16,181 Points 
var size = 8;

var board = "";

for (var y = 0; y < size; y++) {
  for (var x = 0; x < size; x++) {
    if ((x + y) % 2 == 0)
      board += " ";
    else
      board += "#";
  }
  board += "\n";
}
console.log(board);

You define the board size (it is a square, so equal columns and rows)

You initialise the board to an empty string

You loop 8 times for the rows

Within the rows loop, you loop 8 times for the columns

If the sum is divisible by 2 (the % operator is called modulus and returns the remainder of a division), then add a space to the board, otherwise add a hashtag (shorter - for every other square, add a hashtag)

When the columns loop is over, add a carriage return and new line

When the rows loop is over, print out the board

Dani Ivanov
Dani Ivanov
10,732 Points

Thanks