swift - How to add two collection view cell by indexPath? -

lets got 4 collection view cells :

if going replace 2 collection view cell @ cell 3 , cell 4 position :

as can see,cell 3 , cell 4 goes down , new cell 1 , cell 2 replace position.

is there way can @ uicollectionview?

i beginner @ using uicollectionview because app development full of tableview usage.so,i want learn more.

any code appreciated.github repo of example more appreciated.

thanks.

from here took sample project collection view , did modification in per requirement.

and below complete code updating collection array when user press button on view.

import uikit  class viewcontroller: uiviewcontroller, uicollectionviewdelegateflowlayout, uicollectionviewdatasource, customcollectionviewcelldelegate {      @iboutlet weak var overlayview: uiview!      @iboutlet weak var collectionview: uicollectionview!      @iboutlet weak var overlaylabel: uilabel!      var purchasecount:float = 0.0      //your collection view data source @ start.     var cellarray = ["cell 1", "cell 2", "cell 3", "cell 4"]      override func viewdidload() {          super.viewdidload()         let layout: uicollectionviewflowlayout = uicollectionviewflowlayout()         layout.sectioninset = uiedgeinsets(top: 50, left: 25, bottom: 50, right: 25)         layout.itemsize = cgsize(width: 100, height: 100)         collectionview!.collectionviewlayout = layout         collectionview!.datasource = self         collectionview!.delegate = self         collectionview!.registerclass(collectionviewcell.self, forcellwithreuseidentifier: "collectionviewcell")         collectionview!.backgroundcolor = uicolor.blackcolor()     }      func numberofsectionsincollectionview(collectionview: uicollectionview) -> int {          return 1     }      func collectionview(collectionview: uicollectionview, numberofitemsinsection section: int) -> int {          return cellarray.count     }      func collectionview(collectionview: uicollectionview, cellforitematindexpath indexpath: nsindexpath) -> uicollectionviewcell {          let cell = collectionview.dequeuereusablecellwithreuseidentifier("collectionviewcell", forindexpath: indexpath) as! collectionviewcell         cell.backgroundcolor = uicolor.blackcolor()         cell.textlabel?.text = cellarray[indexpath.row]         cell.imageview?.image = uiimage(named: "circle")         cell.imageviewstar?.image = uiimage(named: "star")         cell.delegate = self         return cell     }      //action when user press button view     @ibaction func addnewcell(sender: anyobject) {          //insert element collection array.         cellarray.insert("new cell 1", atindex: 2)         cellarray.insert("new cell 2", atindex: 3)          //reload collection view.         self.collectionview.reloaddata()     }      // mark: customcollectionviewcelldelegate      func starimagehit(price:float) {         print("star image hit in view controller")         self.purchasecount = self.purchasecount + price         self.overlayview.hidden = false         self.overlayview.alpha = 1.0         self.overlaylabel.text = "\(self.purchasecount)"        uiview.animatewithduration(1.0, delay: 0.0, options: uiviewanimationoptions.curveeaseout, animations: {             self.overlayview.alpha = 0.0             self.view.layoutifneeded()         }, completion: nil)     }  } 

and result:

and here sample project you.