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

There is something about Array.fill I need to mention.

If you just use below method to create a 3x3 matrix.

Array(3).fill(Array(3).fill(0));

You will find that the values in the matrix is a reference.

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Optimized solution (prevent passing by reference):

If you want to pass by value rather than reference, you can leverage Array.map to create it.

Array(3).fill(null).map(() => Array(3).fill(0));