CollectionView sections - swift

Question

I have a collectionview and I want it to be of n section where each section has a ten of cells, my problem is: Maybe n equals thirty five, in this case I want to show 3 section with ten of cells and the last section with just five.

Answer 1

If array count is 35 return count/10 if count%10 is 0 else return count/10+1 in numberOfSections method
In numberOfItemsInSection method multiply current section with 10 and subtract from count. return min value of 10 or subtracted value
In cellForItemAt method multiply section with 10 and add row to get the array index
class ViewController: UIViewController, UICollectionViewDataSource {
var arr = Array(1...35)
func numberOfSections(in collectionView: UICollectionView) -> Int {
return (arr.count/10) + (arr.count%10 == 0 ? 0 : 1)
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return min(10,arr.count - (10*section))
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath) as? Cell
let currentStr = arr[(indexPath.section*10)+indexPath.item]
cell?.label.text = "\(currentStr)"
return cell!
}
}

Answer 2

You can simply implement UICollectionViewDataSource methods and configure collectionView(_:numberOfItemsInSection:) method based on the each section for number of cells.
let n = 35 //It specify the total elements count
func numberOfSections(in collectionView: UICollectionView) -> Int {
return n/10
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
switch section {
case (n/10):
return (n % 10)
default:
return 10
}
}
In the above code, the collectionView will have
(n % 10) cells for last section
10 cells for other sections
Kindly clarify your conditions so I can update the code accordingly.

Answer 3

You can split the array into chunks using this extension
extension Array {
func chunked(into size: Int) -> [[Element]] {
return stride(from: 0, to: count, by: size).map {
Array(self[$0 ..< Swift.min($0 + size, count)])
}
}
}
If count is 35 -> [10,10,10,5]
If count is 30 -> [10,10,10]
If count is 29 -> [10,10,9]
Then use the two dimensional array in collectionview delegate methods
class ViewController: UIViewController, UICollectionViewDataSource {
let array = Array(1...35)
lazy var chunkedArray = array.chunked(into: 10)
func numberOfSections(in collectionView: UICollectionView) -> Int {
return chunkedArray.count
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return chunkedArray[section].count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath)
print(chunkedArray[indexPath.section][indexPath.item])
return cell
}
}