unichar c1 = 'A';

bool isLetter = [[NSCharacterSet
    letterCharacterSet]
    characterIsMember:c1];
//isLetter is 1

bool isNumber = [[NSCharacterSet
    decimalDigitCharacterSet]
    characterIsMember:c1];
//isNumber is 0

NSString *symbolList = @"@#$%^&*";
bool isInList = [symbolList
    containsString:@"$"];
//isInList is 1