ios - Swift 3 - How to remove all Subviews from Superview as well as Array -

i have double for-loop creates x y grid of uiview cgrect squares. loop adds each uiview/square of grid 2d array allowing me access each cell of grid , alter color/positioning index values of loop.

the loop seems work fine , displays cells/squares perfectly, after while want remove of squares , empty array (but not entirely delete) make room new next grid (which may of different size). created function remove views superview.

this how creating each "cell" of grid , placing each 2d array:

let xstart = int(size.width/2/2) - ((gridsizex * gridscale)/2) let ystart = int(size.height/2/2) - ((gridsizey * gridscale)/2)  let cell : uiview! cell = uiview(frame: cgrect(x: xstart + (xpos * gridscale), y:ystart + (ypos * gridscale), width:gridscale, height:gridscale))  cell.layer.borderwidth = 1 cell.layer.bordercolor = uicolor(red:0.00, green:0.00, blue:0.00, alpha:0.02).cgcolor cell.backgroundcolor = uicolor(red:1.00, green:1.00, blue:1.00, alpha:0)  cell.tag = 100  self.view?.addsubview(cell)  gridarray[xpos][ypos] = cell 

the 2d array being created on application load so:

gridarray = array(repeating: array(repeating: nil, count: gridsizey), count: gridsizex) 

i have tried search solution remove uiviews superview answers other questions don't seem work me. have tried add cell.tag = 100 each uiview , remove uiviews tag value of 100 like:

for subview in (self.view?.subviews)! {     if (subview.tag == 100) {         subview.removefromsuperview()     } } 

however no luck. have tried use method:

self.view?.subviews.foreach({     $0.removeconstraints($0.constraints)     $0.removefromsuperview() }) 

the main differences notice in code compared other peoples answers have "?" , "!" @ places in code. researched mean , understood of still not know how fix code because if it, , feel though issue. know attempts remove uiviews superview not work, , without "?" , "!"s code doesn't run @ all.

how create tag each cell using example:

    //init value for tag.     var n = 0      func preparecell() -> uiview {              let xstart = int(size.width/2/2) - ((gridsizex * gridscale)/2)              let ystart = int(size.height/2/2) - ((gridsizey * gridscale)/2)           let cell : uiview!          cell = uiview(frame: cgrect(x: xstart + (xpos * gridscale), y:ystart + (ypos * gridscale), width:gridscale, height:gridscale))           cell.layer.borderwidth = 1          cell.layer.bordercolor = uicolor(red:0.00, green:0.00, blue:0.00, alpha:0.02).cgcolor          cell.backgroundcolor = uicolor(red:1.00, green:1.00, blue:1.00, alpha:0)          cell.tag = n          //each cell should have new value         n += 1          return cell } 

and remove required views.

func removeviews() {     z in 0...n {         if let viewwithtag = self.view.viewwithtag(z) {            viewwithtag.removefromsuperview()         }         else {            print("tag not found")         }     } } 

example working in playground:

var n = 0  let mainview = uiview()  func createview() -> uiview {     let view = uiview()     view.tag = n     n += 1     return view }  in 0...16 {     mainview.addsubview(createview()) }  func removeviews() {     z in 0...n {         if let viewwithtag = mainview.viewwithtag(z) {             viewwithtag.removefromsuperview()              print("removed")         }         else {             print("tag not found")         }     } }