EXC_BAD_INSTRUCTION runtime error

Question

Why does the first line in the method below give me an EXC_BAD_INSTRUCTION runtime error?

func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! {
    let cellIdentifier = NSStringFromClass(MessageCell)
    var cell = tableView.dequeueReusableCellWithIdentifier(cellIdentifier) as MessageCell
    // ...
}

score 1 · Answer 1 · edited May 23 '17 at 10:32

1

Swift does not have the introspection capabilities yet as Obj-C does.

class Cell: UITableViewCell {

}

let a = NSStringFromClass(NSString) // prints NSString
let b = NSStringFromClass(Cell) // prints _TtC11lldb_expr_04Cell
let c = NSStringFromClass(UITableViewCell) // prints UITableViewCell

Since the identifier gets modified you try to dequeue a non-existent cell which leads to the mentioned error.

See also Get a user-readable version of the class name in swift (in objc NSStringFromClass was fine)

edited May 23 '17 at 10:32

Community

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answered Jul 02 '14 at 17:06

artey

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Good guess. But, I was actually using `cellIdentifier` in both places. Thanks though. I figured it out. – ma11hew28 Jul 02 '14 at 17:16

score 0 · Answer 2 · edited May 23 '17 at 10:32

0

Actually, turns out the first line is OK. It was the second line causing the crash. UITableView in Swift has the solution.

edited May 23 '17 at 10:32

Community

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answered Jul 02 '14 at 17:12

ma11hew28

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yeah, the one in which you are dequeuing the cell. – artey Jul 02 '14 at 17:14

EXC_BAD_INSTRUCTION runtime error

2 Answers2