Question

How to check whether a string contains whitespaces in between characters?

Answer 1

use rangeOfCharactersFromSet:

NSString *foo = @"HALLO WELT";
NSRange whiteSpaceRange = [foo rangeOfCharacterFromSet:[NSCharacterSet whitespaceCharacterSet]];
if (whiteSpaceRange.location != NSNotFound) {
    NSLog(@"Found whitespace");
}

note: this will also find whitespace at the beginning or end of the string. If you don’t want this trim the string first…

NSString *trimmedString = [foo stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
NSRange whiteSpaceRange = [trimmedString rangeOfCharacterFromSet:[NSCharacterSet whitespaceCharacterSet]];