iOS: Realm, check if the object is nil

Question

I have this code where I populate an array:

func loadObjectsFromRealm() {
    private var myObjects: [MyObjects] = []
    guard let realm = try? Realm() else { return }
    myObjects = realmUtility.getAll(realm)
}

how can I check if the object is nil or not when I am going to use them? For example:

func getFirst() {
var myFirstObj = myObjects[0]    
}

Is there something to check if the object myFirstObject is real or not?

I am not much concerned with the issue, but i think guard will not allow the nil object to be store in your realm as it will execute the else block and return. so no need to check for nil latter. Are you getting any nil object?? — Janmenjaya, Sep 16 '16 at 06:43
If your concern is to check nil You can do by this if (myFirstObj == nil){ print("No object to see here") }else{ print("myFirstObj = \(myFirstObj)"); } — Janmenjaya, Sep 16 '16 at 06:49
Possible duplicate of [Safe (bounds-checked) array lookup in Swift, through optional bindings?](http://stackoverflow.com/questions/25329186/safe-bounds-checked-array-lookup-in-swift-through-optional-bindings) — HAS, Sep 16 '16 at 07:04

andromedainiative · Answer 1 · 2017-10-12T10:37:56.903

3

// Check for specific object with primary key

func objectExist (id: String) -> Bool {
        return realm.object(ofType: MyObject.self, forPrimaryKey: id) != nil
}

// Returns true or false
objectExist(id: "1")

edited Oct 12 '17 at 10:37

answered May 10 '17 at 14:58

andromedainiative

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The ternary expression is not necessary here. The boolean comparison will return what you want directly without having to add any extra syntax – Michael Hulet Oct 11 '17 at 16:23
Thanks, changed the answer. – andromedainiative Oct 12 '17 at 10:38

Orlando · Answer 2 · 2016-09-16T06:35:46.120

1

You can try an usual Swift if statement:

if let myFirstObj = myObjects.first
   // Do anything with the first object
} else {
   print("No first object!")
}

I think that's enough for this case.

edited Sep 16 '16 at 06:35

answered Sep 16 '16 at 06:27

Orlando

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Using subscripts does not check whether or not the index is valid, use `.first` instead. – HAS Sep 16 '16 at 06:33
I wrote first... but it could have whatever index – cyclingIsBetter Sep 16 '16 at 06:47

score 1 · Answer 3 · answered Apr 17 '18 at 04:50

1

I wanted to comment on the answer by @andromedainiative, but I don't have enough rep points.

'id' can't be a String - needs to be an Int;

func objectExists(id: Int) -> Bool {
        return realm.object(ofType: MyObject.self, forPrimaryKey: id) != nil
    }

//Returns true of false

objectExists(1)

answered Apr 17 '18 at 04:50

Joey Slomowitz

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That is not true at all: https://stackoverflow.com/questions/26152254/how-to-set-primary-key-in-swift-for-realm-model – andromedainiative Apr 30 '18 at 12:51
@andromedainiative. Checking the id using an Int is working 100% for me. Were you able to get it working using the String value? I noticed the answer you're referencing is a couple years old. – Joey Slomowitz May 07 '18 at 04:53

score 0 · Answer 4 · answered Sep 16 '16 at 07:02

I tried it following way, you can check like this. Here I have just created a nil object and checked, you can do the same for your object

 let obj :UserProfile? = nil;

    if (obj == nil){
        print("nil objUser");
    }else{
        print("objUser = \(objUser)")
    }

output : nil objUser

larva · Answer 5 · 2016-09-16T07:20:31.200

0

you may check object is really exist before access it

if var myObj: MyObjects = myObjects.indices.contains(index) ? myObjects[index] : nil {
    // myObj is exist
}

edited Sep 16 '16 at 07:20

answered Sep 16 '16 at 07:13

larva

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iOS: Realm, check if the object is nil

5 Answers5