iOS

Solution: Constraint are very easy if you understand that with logically.First you have to think your need for design then proceed that. It had an alignments that with left,right,top,bottom also width,height and center of the view. If your view wants to be aligned left then first set the left,top and bottom.If the width varies based on the view then don't set the width.Also height too... If your two views or buttons wants to be the same width.then select both the views and select that option called equal width. If you wants that view wants to be aligned vertically or horizontally to the superview then select the view and check the options.

Solution: If you are setted the insets in storyBoard you want to set in both sides.Like if you set the inset in bottom 2 then set the top to -2 (or) if you set the left to 2 then set right to -2. It will solve your problem.Also check that if you set the image in didselect then it might be the problem.So check carefully to set the different image when select the tab bar. Also check the constraints.

Solution: Apple had a magic technics for distribution.They had the tool named testFlight with internal and external testers to review the app and testing purpose. If you want to distribute an app with other then you have to export the IPA file with it's provisioning profiles and upload it to Diawi or some other sites then send the link to the customer or tester. And one more if you had a enterprise account it's very easy you can export the app and upload it to your website and send the link to the tester.

Solution: In NSDictionary you cannot be able to change the value.If you can convert the NSDictionary to NSMutableDictionary then you can change the value in it.              var dic =  dataArray . object (at: 0 ) as ! NSDictionary             let mute = NSMutableDictionary ()             mute. addEntries (from: dic as ! [ AnyHashable : Any ])                  mute. setValue ( "value" , forKey: "keyValue" )             self . dataArray . replaceObject (at: 0, with: NSDictionary (dictionary: mute))