How to check if NSDictionary has key-value pair?

Question

I have seen answers aleready posted, they all are talking about... using objectForKey method on NSDictionary, which is not proper if we dont know the key's.

How can you check for a particular key-value pair if you don't know the key you're looking for? How will you know if you found it? — rdelmar, Jun 09 '15 at 04:52
If you want to know, if there is a key you do not know, you can simply use `@voodoo` as key. — Amin Negm-Awad, Jun 09 '15 at 05:00
if you allocated NSDictinaory ,and then trying to find if it has added with some object,in this case how can you use "objectForKey"? — Vinod Supnekar, Jun 09 '15 at 05:01
possible duplicate of [How to check if an NSDictionary or NSMutableDictionary contains a key?](http://stackoverflow.com/questions/2784648/how-to-check-if-an-nsdictionary-or-nsmutabledictionary-contains-a-key) — Droppy, Jun 09 '15 at 05:14

liushuaikobe · Accepted Answer · 2015-06-09T05:10:27.260

3

You can use the count property to test if a NSDictionary has any entries.

if (aDic.count == 0) {
    // aDic is empty.
} else {
    // aDic has some entries.
}

And, you can use the objectForKey: method to test if a specific entry exist.

For example, I want to know if a key named "foo" exist in the dictionary:

if ([aDic objectForKey:@"foo"] != nil) {
    // aDic has a entry named "foo"
} else {
    // "foo" doesn't exsits
}

Also, you can simplify this:

if (aDic[@"foo"]) {
    // aDic has a entry named "foo"
} else {
    // "foo" doesn't exsits
}

edited Jun 09 '15 at 05:10

answered Jun 09 '15 at 05:04

liushuaikobe

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yaah...i was thinking about it a while about ..if (aDic.count == 0) {}..and it did the trick...Thank you. – Vinod Supnekar Jun 09 '15 at 05:07
@VinodSupnekar Have I explain it clearly? If so, please accept my answer, it's important to me, thanks. – liushuaikobe Jun 09 '15 at 05:08
@VinodSupnekar Glad to help. I add some comments to help you understand it better. – liushuaikobe Jun 09 '15 at 05:10

score -2 · Answer 2 · edited Jun 09 '15 at 09:23

-2

if ([yourDictionary isKindOfClass:[NSDictionary class]])
{
    NSLog(@"%@",yourDictionary)
}

edited Jun 09 '15 at 09:23

fedorqui

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answered Jun 09 '15 at 05:14

Mohak

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add some explanation on how this works, otherwise it has very little value – fedorqui Jun 09 '15 at 09:23
How would checking if `NSDictionary` is of `NSDictionary` class solve anything. – Popeye Jun 24 '15 at 07:48

How to check if NSDictionary has key-value pair?

2 Answers2