How can I create a two dimensional array in JavaScript?

Question

I have been reading online and some places say it isn\'t possible, some say it is and then give an example and others refute the example, etc.

1. How do I dec

Answer 1

Few people show the use of push:
To bring something new, I will show you how to initialize the matrix with some value, example: 0 or an empty string "".
Reminding that if you have a 10 elements array, in javascript the last index will be 9!

function matrix( rows, cols, defaultValue){

  var arr = [];

  // Creates all lines:
  for(var i=0; i < rows; i++){

      // Creates an empty line
      arr.push([]);

      // Adds cols to the empty line:
      arr[i].push( new Array(cols));

      for(var j=0; j < cols; j++){
        // Initializes:
        arr[i][j] = defaultValue;
      }
  }

return arr;
}

usage examples:

x = matrix( 2 , 3,''); // 2 lines, 3 cols filled with empty string
y = matrix( 10, 5, 0);// 10 lines, 5 cols filled with 0