Uncaught TypeError: Cannot read property '1' of undefined (even though it is defined)

Question

所以我们的老师给了我们 "Game Of Life" 项目。在我运行它并得到错误 "Uncaught TypeError: Cannot read property '1' of undefined" 之前，我真的为我的项目感到自豪。对于那些不知道什么是 Game Of Life 的人来说，它是一个 "game"，其中有一个矩阵（这里是一个 8x8 矩阵）和一些规则来定义每个 "person"（矩阵中的数字）活不活。 1代表活着，0代表死了。我将附上整个项目以供参考，但这是错误的部分：

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;
}

错误出现在 if (neighbors < 2) {nextgen[i][j] = 0;}。任何人都知道为什么？我在为nextgen[1]定义8个数组时定义了nextgen[1][1]，对吧？

这是整个项目。名字和一切都是德语，所以请记住这一点。

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>

Answer 1

我发现了问题所在。它在 berechne_nachbarn 函数中，程序在这里计算游戏板上每个单元格的邻居。这部分更具体：

if (y == 8) {rechts = 8} else {rechts = y - 1}

y - 1 应该是 y + 1。

Ps。该程序现在可以运行了，我为此感到自豪^_^

Uncaught TypeError: Cannot read property '1' of undefined (even though it is defined)

Uncaught TypeError: Cannot read property '1' of undefined (even though it is defined)

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