挤压空格

NSString *string = @"Lorem    ipsum dolar   sit  amet.";string = [string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];NSArray *components = [string componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];components = [components filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:@"self <> ''"]];string = [components componentsJoinedByString:@" "];