Protect against nil in for loop

Question

I've been getting this error...

[2017-02-27 15:11:23] NONE us us_crdrscrdrsge NONE [2017-02-27 15:11:23] brea crdrs crdrs_ar united states [2017-02-27 15:11:23] brea crdrs crdrs_daz1 united states [2017-02-27 15:11:23] brea crdrs crdrs_dev united states [2017-02-27 15:11:23] brea crdrs crdrs_devgen united states [2017-02-27 15:11:24] NONE us us_ctabscaninv NONE [2017-02-27 15:11:24] NONE us us_ctabscanstmt NONE fatal error: unexpectedly found nil while unwrapping an Optional value 2017-02-27 15:11:24.111276 Mobile[647:47234] fatal error: unexpectedly found nil while unwrapping an Optional value

How can I protect against nil values in this for loop:

```

  let apResults = realm.objects(DestinationNoEnum.self).
           filter("destinationRegionCode = 'ap'")


  for aps in apResults {
        autoreleasepool {
        print("\(aps.destinationCity) \(aps.destinationCode) 
         \(aps.destinationName) \(aps.destinationCountry)")
        }}

the apResults array is created via a realm query. There's like 1000 entries in the db.

This http://stackoverflow.com/questions/32170456/what-does-fatal-error-unexpectedly-found-nil-while-unwrapping-an-optional-valu looks like it has two good answers. Either explicitly check if aps != nil , or use their example for optional biding — Gonen I, Feb 27 '17 at 23:58
Can you share the code for your `aps` entity? I don't think you should get back nil elements when iterating `apResults`. — Dave Weston, Feb 28 '17 at 00:29

score 2 · Accepted Answer · answered Feb 28 '17 at 00:08

2

Try this:

for aps in apResults where aps != nil {
    // do your things
}

answered Feb 28 '17 at 00:08

Code Different

90,614
16
144
163

Petr Šmejkal · Answer 2 · 2023-04-03T17:50:59.473

0

This should do what you need:

for case let aps? in apResults {
    // use aps which is ".some" value
}

edited Apr 03 '23 at 17:50

answered Mar 29 '23 at 14:19

Petr Šmejkal

1
1

1

A good answer should explain how it works and how it solves the issue in the question. – HangarRash Apr 04 '23 at 16:46
@HangarRash And that's exactly what it does. – Petr Šmejkal Apr 05 '23 at 17:12

Protect against nil in for loop

2 Answers2