Declare an empty two-dimensional array in Javascript?
You can just declare a regular array like so:
var arry = [];
Then when you have a pair of values to add to the array, all you need to do is:
arry.push([value_1, value2]);
And yes, the first time you call arry.push
, the pair of values will be placed at index 0.
From the nodejs repl:
> var arry = [];undefined> arry.push([1,2]);1> arry[ [ 1, 2 ] ]> arry.push([2,3]);2> arry[ [ 1, 2 ], [ 2, 3 ] ]
Of course, since javascript is dynamically typed, there will be no type checker enforcing that the array remains 2 dimensional. You will have to make sure to only add pairs of coordinates and not do the following:
> arry.push(100);3> arry[ [ 1, 2 ], [ 2, 3 ], 100 ]
ES6
Matrix m
with size 3 rows and 5 columns (remove .fill(0)
to not init by zero)
[...Array(3)].map(x=>Array(5).fill(0))