Declare an empty two-dimensional array in Javascript?

Question

I want to create a two dimensional array in Javascript where I\'m going to store coordinates (x,y). I don\'t know yet how many pairs of coordinates I will have because they

Answer 1

An empty array is defined by omitting values, like so:

v=[[],[]]
a=[]
b=[1,2]
a.push(b)
b==a[0]