CODEWITHSUNDEEP
iosiphoneobjective-cstringsearch
TommyG
TommyG

Reputation: 4155

case insensitive string search - iphone

I am looking for a way to perform a case insensitive string search within another string in Objective-C. I could find ways to search case sensitive strings, and to compare insensitive case, but not searching + case insensitive.

Examples of the search that I would like to perform:

"john" within "i told JOHN to find me a good search algorithm"

"bad IDEA" within "I think its a really baD idea to post this question"

I prefer to stick to only NSStrings.

Upvotes: 9

Views: 14034

Answers (4)

Majestic12
Majestic12

Reputation: 216

If you're using ios 8, you can use NSString's localizedCaseInsensitiveContainsString

- (BOOL)localizedCaseInsensitiveContainsString:(NSString *)aString

localizedCaseInsensitiveContainsString: is the case-insensitive variant. Note that it takes the current locale into effect as well. Locale-independent case-insensitive operation, and other needs can be achieved by calling rangeOfString:options:range:locale: directly.

Upvotes: 8

Zorayr
Zorayr

Reputation: 24902

Here is a self-container solution for Swift:

private func containsKeyword(text: NSString, keyword: String) -> Bool
{
  return text.rangeOfString(keyword, options:NSStringCompareOptions.CaseInsensitiveSearch).location != NSNotFound
}

Upvotes: 0

Seva Alekseyev
Seva Alekseyev

Reputation: 61351

NSRange r = [MyString rangeOfString:@"Boo" options:NSCaseInsensitiveSearch];

Feel free to encapsulate that into a method in a category over NSString, if you do it a lot. Like this:

@interface NSString(MyExtensions)
-(NSRange)rangeOfStringNoCase:(NSString*)s;
@end

@implementation NSString(MyExtensions)
-(NSRange)rangeOfStringNoCase:(NSString*)s
{
    return  [self rangeOfString:s options:NSCaseInsensitiveSearch];
}
@end

Your code might become more readable with this. Then again, less readable for those unfamiliar.

Upvotes: 31

Mark
Mark

Reputation: 509

mistagged as c#?

heres some advice for objc

NSRange textRange = [[string lowercaseString] rangeOfString:[substring lowercaseString]];

if(textRange.location != NSNotFound)
{
//Does contain the substring
}

which i got from google at this webpage: http://www.developers-life.com/does-a-nsstring-contain-a-substring.html

does that help your scenario?

Upvotes: 9

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