Last active
October 25, 2019 04:52
-
-
Save ericyd/b342e6bc28200eab1e304481bdbc17d5 to your computer and use it in GitHub Desktop.
Two dimensional array in JS
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| /* | |
| It is common to address two-dimensional array problems with nested arrays. | |
| It works, but then you have all these nasty references like array[0][3]. | |
| This class abstracts the element selection to a method which takes the x and y indices | |
| as arguments. | |
| If you wanted to go purely functional obviously you can, but this class demonstrates the idea. | |
| */ | |
| class TwoDimensionalArray { | |
| constructor(array, xDim) { | |
| if (array.length % xDim !== 0) { | |
| throw new Error(`Your array is not rectangular! Length: ${array.length}, x-dimension: ${xDim}`) | |
| } | |
| this.array = array | |
| this.xDim = xDim | |
| } | |
| index(x, y) { | |
| return this.array[(y * this.xDim) + x] | |
| } | |
| } | |
| const incrementalArray = size => new Array(size).fill(0).map((_, i) => i) | |
| const xDim = 4 | |
| const yDim = 3 | |
| const twoDArr = new TwoDimensionalArray(incrementalArray(xDim * yDim), xDim) | |
| // access elements in our array | |
| const xs = incrementalArray(xDim) | |
| const ys = incrementalArray(yDim) | |
| ys.forEach(y => { | |
| xs.forEach(x => { | |
| console.log(`x: ${x}, y: ${y}, res: ${twoDArr.index(x, y)}`) | |
| }) | |
| }) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment