How do you easily create empty matrices javascript?

Question

In python, you can do this:

[([None] * 9) for x in range(9)]

and you\'ll get this:

[[None, None, None, None, None, None, No         


        

Answer 1

You can add functionality to an Array by extending its prototype object.

Array.prototype.nullify = function( n ) {
    n = n >>> 0;
    for( var i = 0; i < n; ++i ) {
        this[ i ] = null;
    }
    return this;
};

Then:

var arr = [].nullify(9);

or:

var arr = [].nullify(9).map(function() { return [].nullify(9); });