Uncaught TypeError: Cannot read property '0' of undefined[es6 learning]

Question

That error occurs most often in my codes... I spent an hour thinking what's wrong. I'm trying to assign each of the divs an action function changing it's color to black and I'm getting an annoying error: Cannot read property '0' of undefined. Please help, my code:
https://code.sololearn.com/WZ7tjp0roE7X/#html

Answer 1

Hi Amadeus, area getter is called without brackets in the lesson, but declared with

Answer 2

but you're for sure right: not this.cells, but this.Cells

Answer 3

Mike Choy Oh thanks, now I understood. As in c#

Answer 4

Hi Amadeus

Just had a quick look, and its failing on this.cells should it be this.Cells?

for(let m=0; m<this.yCount; m++){
$("body").append("<div></div>");
this.cells[l][m] = $("body div").last();
$(this.cells[l][m]).addClass("cell");
$(this.cells[l][m]).css({

Answer 5

Hi, Mike Choy
Thanks for support, but in the lesson "class methods"
https://www.sololearn.com/learn/518/?ref=app
they used the following getter for the calcArea method...
get area() {
return this.calcArea();
}

calcArea() {
return this.height * this.width;
}

Answer 6

Hi Amadeus

And finally you are calling your getters wrong;
Should be

board.Create;
board.AllowMark;

no brackets as its not a method.
It runs and paints one big long vertical bar, so some more work to do
but hopefully that gets you going again