Javascript how to create an array of arrays

Question

Could somebody please help me to create an array of array.I have a matrix calculator and I want to create an array of arrays ('smaller').How can I do it?The functiions create2Darray and calculateDet are working ok,so now problem with them.Would be really grateful for the help.I need an array of these arrays (main matrix's minors) to calculate their determinants and calculate the inverted matrix Here is the HTML:

<div id = "table4">
<div class = "calcHeader">Macierz odwrotna [3x3]</div>
<form id = "row1"><!--first row-->
 <input type = "text" class = "det3"/>
 <input type = "text" class = "det3"/>
 <input type = "text" class = "det3"/>
 </form>
 <form id = "row2"><!--second row-->
 <input type = "text" class = "det3"/>
 <input type = "text" class = "det3"/>
 <input type = "text" class = "det3"/>
</form>
<form id = "row3"><!--third row-->
 <input type = "text" class = "det3"/>
 <input type = "text" class = "det3"/>
 <input type = "text" class = "det3"/>
</form>
<div class = "count" onclick="invertMat('det3')"><a href = "#">Wylicz</a></div>
</div>

Javascript

function invertMat(matrixClass) {
 var matrix = create2Darray(matrixClass);
 var det = calculateDet(matrix);
 //alert(det);
 var invMat = new Array();
 for (var i = 0; i < matrix.length; i++) {
 invMat[i] = new Array();
 for (var j = 0; j < matrix.length; j++) {
 invMat[i][j] = 0;
 }
 }
 if (matrix.length == 2) {
 invMat[0][0] = 1 / det * matrix[1][1];
 invMat[1][0] = 1 / det * (-matrix[1][0]);
 invMat[0][1] = 1 / det * (-matrix[0][1]);
 invMat[1][1] = 1 / det * matrix[0][0];
 alert(invMat);
 } else if (matrix.length == 3) {
 //var smaller = new Array();//creating an empty array for a matrix minor
 for (var i = 0; i < matrix.length; i++) {
 var smaller = new Array(matrix.length - 1);
 for (h = 0; h < smaller.length; h++) {
 smaller[h] = new Array(matrix.length - 1);
 }
 for (a = 1; a < matrix.length; a++) {
 for (b = 0; b < matrix.length; b++) {
 if (b < i) {
 smaller[a - 1][b] = matrix[a][b];
 } else if (b > i) {
 smaller[a - 1][b - 1] = matrix[a][b];
 }
 }
 }
 }
 }
}

Answer 1

Try Like this Fiddle

var array1 = new Array();
array1.push(1);
array1.push(2);
var array2 = new Array();
array2.push(3);
array2.push(4);
var array3 = new Array();
array3.push(array1);
array3.push(array2);
console.log(array3[0]);
console.log(array3[1]);

Answer 2

Live demo

function create2Array(d1, d2, fn) {
 var arr = [],
 d = function(x, y) {},
 f = fn || d;
 for (var i = 0; i < d1; i++) {
 for (var j = 0, curr = []; j < d2; j++) {
 curr[j] = f.call(window, i, j); 
 };
 arr[i] = curr;
 };
 return arr;
};
function print2DArray(arr) {
 document.body.innerHTML += "<p><b>Array:</b></p>";
 for (var i = 0, len = arr.length; i< len; i++) {
 document.body.innerHTML += "<p><b>" + i + "</b>: " + arr[i].join(" ") + "</p>";
 };
};
var matrix = create2Array(10, 10, function(x, y) { return 0;}),
 m2 = create2Array(10, 10, function(x, y) { return x + y;});
print2DArray(matrix);
print2DArray(m2);

Use it like this:

var matrix = create2Array(10, 10);

Or you can even specify a custom init function which takes the index as param. Say if you want to init your matrix with 0 by default:

var matrix = create2Array(10, 10, function(x, y) { return 0;});