How to declare and initialize 2-dimensional array

@a = ( [1, 2, 3], [4, 5, 6], [7, 8, 9] ); # @a is an array with three elements, and each one is a reference # to another array. # $a[1]->[2] is the 6. Similarly, # $a[0]->[1] is the 2. # two-dimensional array; you can write $a[ROW]->[COLUMN]