Is there an easy way to programmatically create a 2d array in javascript?
What I don't want:
var array2D = [
[0,0,0],
[0,0,0],
[0,0,0]
]
views:
81answers:
2
+2
A:
Well, you could write a helper function:
function zeros(dimensions) {
var array = [];
for (var i = 0; i < dimensions[0]; ++i) {
array.push(dimensions.length == 1 ? 0 : zeros(dimensions.slice(1)));
}
return array;
}
> zeros([5, 3]);
[[0, 0, 0], [0, 0, 0], [0, 0, 0], [0, 0, 0], [0, 0, 0]]
Bonus: handles any number of dimensions.
John Kugelman
2010-09-11 05:33:14
Marked down you end up with multiple references to the same array
Tom
2010-09-11 05:36:56
@Tom Aye, good call. Rewritten.
John Kugelman
2010-09-11 05:47:24
Change `item` to a lambda that is a factory for items.
Ates Goral
2010-09-11 05:48:34
@John now marked up
Tom
2010-09-11 05:58:58
This could be written much more clearly. Typically when you're writing a recursive function, you should make sure that the base case and inductive case are easily identified. In the code above, both are on the same line -- very confusing. Instead, I would recommend that you check the `dimensions.length === 1` conditional at the top of the function and that you create two `for` loops -- one that creates an array of 0s (the base case) and one that creates an array with `zeros` function calls (the inductive case). Though the resulting code will be more verbose, it's much less confusing.
Xavi
2010-09-11 06:19:59
+1
A:
function zero2D(rows, cols) {
var array = [], row = [];
while (cols--) row.push(0);
while (rows--) array.push(row.slice());
return array;
}
MooGoo
2010-09-11 06:01:38