CODEWITHSUNDEEP
ios
agierens
agierens

Reputation: 132

Searching an array for a string

What I am trying to achieve is to search an array for a string, here is the code for searching the array

    if ([EssentialsArray containsObject:imageFilePath]) {

        NSLog(@"YES");
    }
    else {

        NSLog(@"NO");
        NSLog(@"%@", ImageFilePath);
        NSLog(@"%@", EssentialsArray);
    }

The NSLogs return this for the imageFilePath:

/var/mobile/Applications/5051DC84-CAC8-4C1D-841D-5539A1E28CB1/Documents/12242012_11025125_image.jpg

And this for the EssentialsArray:

(
        {
        EssentialImage = "/var/mobile/Applications/5051DC84-CAC8-4C1D-841D-5539A1E28CB1/Documents/12242012_11025125_image.jpg";
    }
)

And then obviously they return a "NO" value because the array couldn't find the string. Thanks in advance

Upvotes: 1

Views: 2436

Answers (1)

Rob
Rob

Reputation: 438467

The issue is that the invocation of [EssentialsArray containsObject:imageFilePath] clearly assumes that EssentialsArray is an array of strings, whereas it's not. It's an array of dictionary entries with one key, EssentialImage.

There are at least two solutions. The first is to make an array of strings for those dictionary entries whose key is EssentialImage:

NSArray *essentialImages = [essentialsArray valueForKey:@"EssentialImage"];

if ([essentialImages containsObject:imagePath])
    NSLog(@"YES");
else
    NSLog(@"NO");

Depending upon the size of your essentialsArray (please note, convention dictates that variables always start with a lower case letter), this seems a little wasteful to create an array just so you can do containsObject, but it works.

Second, and better in my opinion is to use fast enumeration to go through your array of dictionary entries, looking for a match. To do this, define a method:

- (BOOL)arrayOfDictionaries:(NSArray *)array
       hasDictionaryWithKey:(id)key
             andStringValue:(NSString *)value
{
    for (NSDictionary *dictionary in array) {
        if ([dictionary[key] isEqualToString:value]) {
            return YES;
        }
    }

    return NO;
}

You can now check to see if your array of dictionaries has a key called @"EssentialImage" with a string value equal to the string contained by imagePath

if ([self arrayOfDictionaries:essentialsArray
         hasDictionaryWithKey:@"EssentialImage" 
               andStringValue:imagePath])
    NSLog(@"YES");
else
    NSLog(@"NO");

Update:

You can also use predicates:

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"EssentialImage contains %@", imagePath];

BOOL found = [predicate evaluateWithObject:array];

Upvotes: 4

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