How can i allow for dynamic resizing of rows and columns in a multidimensional array, utilizing the .length attribute?

array.length = value // Changes the number of rows
array[1].length = value // changes the number of columns for row 1

Note that you cannot change the number of columns if the row doesn't exist
array.length = 1
array[2].length = 3 // This will fail because row 2 doesn't exist

Thankyou sir