Xcode Object-C init

NSString Init

[NSString stringWithFormat:@"%@/%@",@"str1",@"str2"];

NSDictionary Init

NSDictionary *dir=[NSDictionary dictionaryWithObjectsAndKeys:

                       @"value-a",@"key-a",

                       @"value-b",@"key-b",

                       nil];

NSArray Init

NSArray *ar=@[@"a",@"b",@"c"];

NSMutableArray Init

NSMutableArray *ar=[NSMutableArray arrayWithObjects:@"",@"", nil];