Find one string in another with case insensitive in Objective-C

As similar to the answer provided in the link, but use options.

See - (NSRange)rangeOfString:(NSString *)aString options:(NSStringCompareOptions)mask in Apple doc

NSString *string = @"hello bla bla";

if ([string rangeOfString:@"BLA" options:NSCaseInsensitiveSearch].location == NSNotFound)
{
    NSLog(@"string does not contain bla");
} 
else 
{
    NSLog(@"string contains bla!");
}