Condensing a sparse array in Javascript?
arrays, javascript, sparse-array
Solution
In vanilla JS, works on all browsers:
function filt(a) {
var b = [];
for(var i = 0;i < a.length;i++) {
if (a[i] !== undefined && a[i] !== null) {
b.push(a[i]);
}
}
return b;
}
> filt([1,undefined,3])
[1, 3]
Problem
I have an array of elements where the entries are sparse. How can I easily condense the sparse array into a dense array so that I don't have to keep checking for null and undefined values every time I loop through the data? Here is some example data: ``` var sparse = []; sparse[1] = undefined; sparse[5] = 3; sparse[10] = null; var dense = sparseToDenseArray(sparse); // dense should be [3] ```