Thread:1 Signal SIGAGBRT - ios

Question

Why do I get a Thread:1 Signal SIGAGBRT within this code? I don't know what to change to fix the error. The application starts and as soon as I press the button the app cancels out and gives me an error.
import UIKit
class ViewController: UIViewController {
#IBOutlet var textFieldInput: UITextField!
#IBOutlet var laCelsius: UILabel!
#IBOutlet var laFahrenheit: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func btn(sender: UIButton) {
var c_out = 0.0
var f_out = 0.0
var inputValue = 0.0
let textInput = NSString(string: textFieldInput.text!)
inputValue = textInput.doubleValue
c_out = (inputValue-32)*5/9
f_out = inputValue * 1.8 + 32
self.laCelsius.text = NSString(format: "%3.2f" ,c_out) as String
self.laFahrenheit.text = NSString(format: "%3.2f" ,f_out) as String
}
}
this is the error code:
2016-09-22 14:15:51.669 DegreeCL[19045:1774964] -[DegreeCL.ViewController btnPressed:]: unrecognized selector sent to instance 0x7fa7bb643d40
2016-09-22 14:15:51.674 DegreeCL[19045:1774964] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[DegreeCL.ViewController btnPressed:]: unrecognized selector sent to instance 0x7fa7bb643d40'
*** First throw call stack:
(
0 CoreFoundation 0x000000010de1dd85 __exceptionPreprocess + 165
1 libobjc.A.dylib 0x000000010fbc1deb objc_exception_throw + 48
2 CoreFoundation 0x000000010de26d3d -[NSObject(NSObject) doesNotRecognizeSelector:] + 205
3 CoreFoundation 0x000000010dd6ccfa ___forwarding___ + 970
4 CoreFoundation 0x000000010dd6c8a8 _CF_forwarding_prep_0 + 120
5 UIKit 0x000000010e647a8d -[UIApplication sendAction:to:from:forEvent:] + 92
6 UIKit 0x000000010e7bae67 -[UIControl sendAction:to:forEvent:] + 67
7 UIKit 0x000000010e7bb143 -[UIControl _sendActionsForEvents:withEvent:] + 327
8 UIKit 0x000000010e7ba263 -[UIControl touchesEnded:withEvent:] + 601
9 UIKit 0x000000010e6ba99f -[UIWindow _sendTouchesForEvent:] + 835
10 UIKit 0x000000010e6bb6d4 -[UIWindow sendEvent:] + 865
11 UIKit 0x000000010e666dc6 -[UIApplication sendEvent:] + 263
12 UIKit 0x000000010e640553 _UIApplicationHandleEventQueue + 6660
13 CoreFoundation 0x000000010dd43301 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
14 CoreFoundation 0x000000010dd3922c __CFRunLoopDoSources0 + 556
15 CoreFoundation 0x000000010dd386e3 __CFRunLoopRun + 867
16 CoreFoundation 0x000000010dd380f8 CFRunLoopRunSpecific + 488
17 GraphicsServices 0x00000001124b3ad2 GSEventRunModal + 161
18 UIKit 0x000000010e645f09 UIApplicationMain + 171
19 DegreeCL 0x000000010dc38412 main + 114
20 libdyld.dylib 0x000000011068592d start + 1
21 ??? 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)

Answer 1

The crucial information is
[DegreeCL.ViewController btnPressed:]: unrecognized selector sent to instance ...'
That means in Interface Builder there is somewhere a dead connection to an action btnPressed. Remove it.
You can search for btnPressed with ⇧⌘F.

Answer 2

SIGABRIT - signal is sent due to many reasons but in this case i think you have problem with Memory.
You should turn on All Exeptions with option of po $arg1 it will identify the error.

Answer 3

Select your button from interface builder, then select connection inspector from utilities and check that if you have extra connected action method should be there, remove it by clicking x and your issue will be solved!
It's should be btnPressed as per your crash log!