So our teacher gave us the "Game Of Life" project. I was really proud of my project until I ran it and got the error "Uncaught TypeError: Cannot read property '1' of undefined". For those who don't know what Game Of Life is, it's a "game" where you have a matrix (here an 8x8 matrix) and some rules to define if each "person" (the numbers in the matrix) gets to live or not. 1 means alive and 0 means dead. I'll attach the whole project for reference, but here's the part with the error:
function process(matrix) { //creates the next generation var neighbors = 0, position = '', nextgen = new Array(8); //the matrix has 8 rows for (i = 1; i <= 8; i++) { nextgen[i] = new Array(8); for (j = 1; j <= 8; j++) { neighbors = neighbors(matrix, i, j); //Game Rules if (neighbors < 2) {nextgen[i][j] = 0; } else if (neighbors == 2) {nextgen[i][j] = 1; } else if (neighbors <= 3) {nextgen[i][j] = nextgen[i][j]; } else {nextgen[i][j] = 0;} } } return nextgen; } The error appears at if (neighbors < 2) {nextgen[i][j] = 0;}. Anyone have any ideas as to why? I defined nextgen[1][1] when I defined 8 arrays for nextgen[1], right?
Here's the whole project. the names and everything are in german, so please keep that in mind.
function berechne_nachbarn(matrixb, x, y) { //berechnet die Anzahl der Nachbarn fuer eine Zelle var zelle = 0, nachbarn = 0, oben = 0, unten = 0, links = 0, rechts = 0; //loesung fuer die Randzellen if (x == 1) {oben = 1} else {oben = x - 1} if (y == 1) {links = 1} else {links = y - 1} if (x == 8) {unten = 8} else {unten = x + 1} if (y == 8) {rechts = 8} else {rechts = y - 1} for (i = oben; i <= unten; i++) { for (j = links; j <= rechts; j++) { zelle = parseInt (matrixb[i][j]); //loesung fuer leere Zellen if (isNaN(zelle)) {zelle = 0;} nachbarn = nachbarn + zelle; }//ende for j }//ende for i //die Zelle selbst ist nicht sein eigener Nachbar! nachbarn = nachbarn - matrixb[x][y]; return nachbarn; }//ende berechne_nachbarn; function eingabe() {//erstellt Matrix var spalte = 0, zeile = 0, ort = '' zelle = 0; brett = new Array(8); //8 Zeilen for (i = 1; i <= 8; i++) { brett[i] = new Array(8); //8 Spalten for (j = 1; j <= 8; j++) { ort = i + 'xx' + j; zelle = parseInt(document.formular.elements[ort].value); if (isNaN(zelle)) {zelle = 0;} brett[i][j] = zelle; }//ende for j }//ende for i return brett; }//ende eingabe function verarbeitung(matrix) {//Spielregeln und Verarbeitung var nachbarn = 0, ort = '', nextgen = new Array(8); //neue Matrix fuer neue Generation for (i = 1; i <= 8; i++) { nextgen[i] = new Array(8); for (j = 1; j <= 8; j++) { nachbarn = berechne_nachbarn(matrix, i, j); //Spielregeln if (nachbarn < 2) {nextgen[i][j] = 0; } else if (nachbarn == 2) {nextgen[i][j] = 1; } else if (nachbarn <= 3) {nextgen[i][j] = nextgen[i][j]; } else {nextgen[i][j] = 0;} }//ende for j }//ende for i return nextgen; }//ende verarbeitung function ausgabe(matrix) {//aendert die Werte im Formular var ort = ''; for (i = 1; i <= 8; i++) { for (j = 1; j <= 8; j++) { ort = i + 'xx' + j; document.formular.elements[ort].value = matrix[i][j]; }//ende for j }//ende for i }//ende ausgabe<body> <h1> Game Of Life</h1> <form name = "formular"> <input name = "1xx1" size = "1"> <input name = "1xx2" size = "1"> <input name = "1xx3" size = "1"> <input name = "1xx4" size = "1"> <input name = "1xx5" size = "1"> <input name = "1xx6" size = "1"> <input name = "1xx7" size = "1"> <input name = "1xx8" size = "1"> <br> <input name = "2xx1" size = "1"> <input name = "2xx2" size = "1"> <input name = "2xx3" size = "1"> <input name = "2xx4" size = "1"> <input name = "2xx5" size = "1"> <input name = "2xx6" size = "1"> <input name = "2xx7" size = "1"> <input name = "2xx8" size = "1"> <br> <input name = "3xx1" size = "1"> <input name = "3xx2" size = "1"> <input name = "3xx3" size = "1"> <input name = "3xx4" size = "1"> <input name = "3xx5" size = "1"> <input name = "3xx6" size = "1"> <input name = "3xx7" size = "1"> <input name = "3xx8" size = "1"> <br> <input name = "4xx1" size = "1"> <input name = "4xx2" size = "1"> <input name = "4xx3" size = "1"> <input name = "4xx4" size = "1"> <input name = "4xx5" size = "1"> <input name = "4xx6" size = "1"> <input name = "4xx7" size = "1"> <input name = "4xx8" size = "1"> <br> <input name = "5xx1" size = "1"> <input name = "5xx2" size = "1"> <input name = "5xx3" size = "1"> <input name = "5xx4" size = "1"> <input name = "5xx5" size = "1"> <input name = "5xx6" size = "1"> <input name = "5xx7" size = "1"> <input name = "5xx8" size = "1"> <br> <input name = "6xx1" size = "1"> <input name = "6xx2" size = "1"> <input name = "6xx3" size = "1"> <input name = "6xx4" size = "1"> <input name = "6xx5" size = "1"> <input name = "6xx6" size = "1"> <input name = "6xx7" size = "1"> <input name = "6xx8" size = "1"> <br> <input name = "7xx1" size = "1"> <input name = "7xx2" size = "1"> <input name = "7xx3" size = "1"> <input name = "7xx4" size = "1"> <input name = "7xx5" size = "1"> <input name = "7xx6" size = "1"> <input name = "7xx7" size = "1"> <input name = "7xx8" size = "1"> <br> <input name = "8xx1" size = "1"> <input name = "8xx2" size = "1"> <input name = "8xx3" size = "1"> <input name = "8xx4" size = "1"> <input name = "8xx5" size = "1"> <input name = "8xx6" size = "1"> <input name = "8xx7" size = "1"> <input name = "8xx8" size = "1"> <br> <br> <br> <button type = "button" onClick = "{jetzt = eingabe(); nextgen = verarbeitung(jetzt); ausgabe(nextgen);}"> Next Generation </button> </form> </body>
countNeighbors, I hadmaxY = y -1instead ofy +1, which caused the weird property '-1' error. Another problem was ininput. It gave me an error and said I hadn't defined the matrix. So, before the Game Rules part, I just gave the value 0 to every cell of the board, and then looked at the form and replaced the values with the ones the user had typed in