NSString Category for search string contents

NSString+StringContents.h

//NOTE: containsString is implemented in iOS 8 and later by Apple
// Please use this version if trying to support iOS 7 and below
@interface NSString (StringContents)
- (BOOL)containsString:(NSString*)substring;
- (BOOL)containsString:(NSString*)substring ignoreCase:(BOOL)ignoreCase;
- (BOOL)containsFormat:(NSString*)regex;
@end

NSString+StringContents.m

@implementation NSString (StringContents)
- (BOOL)containsString:(NSString*)substring
{
  return (substring.length && [self rangeOfString:substring].length);
}

- (BOOL)containsString:(NSString*)substring ignoreCase:(BOOL)ignoreCase
{
	if(ignoreCase)
		return (substring.length && [self rangeOfString:substring options:NSCaseInsensitiveSearch].length);
	else
		return (substring.length && [self rangeOfString:substring].length);
}

- (BOOL)containsFormat:(NSString*)regex
{
    NSPredicate *regextest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex];
    return [regextest evaluateWithObject:self];
}

@end