UIAlertView warning (code will never be executed)

hi i'm new ios programming , trying port os x apps ios , i'm stuck in "uialertview" coding keep on getting warning "code never executed"

code:

- (ibaction)popup:(id)sender { uialertview *alertview; alertview = [[uialertview alloc] initwithtitle:@"the title" message:@"" delegate:nil cancelbuttontitle:@"cancel" otherbuttontitles:@"a", @"b" , @"c", nil]; [alertview show];      if (@"a") {          [sender settitle: @"a"forstate:uicontrolstatenormal];      }else if(@"b") { // line  error        }  }

any fix it, cant without "else" in statement whatever last "if statement"

 

first foremost, shouldn't use uialertview it's been deprecated in ios 8 in favor of uialertcontroller. it's more straight forward.

intending if-statement do?

reads, you're creating uialertview, showing it. then, after shown, run if block. mean handle feedback alert? if so, you'll have use delegate pattern, can read about, , other common patterns, here. setting delegate class (not nil, 1 creates alert), , implementing correct method:

code:

- (void)alertview:(uialertview *)alertview clickedbuttonatindex:(nsinteger)buttonindex

when button pressed, alert view fire method delegate, letting know button pressed. (0 = a, 1 = b, 2 = c, in case).

now, why getting error... because it's important see happening here.

code:

if (@"a") {

this always return true, therefore code written in else brackets never run. error telling you. why:

@"a" returns string containing character "a", true because exist. if blocks evaluate statements based on true or false. see issue here?

using comparison allows check against values:

code:

if(@"a" == stringvariable) {

now, tie these 2 concepts - compare buttonindex in alertview:clickedbuttonatindex: determine buttons pressed, , accordingly.

 

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