Should I use NSUserDefaults or a plist to store data?

Sheehan Alam picture Sheehan Alam · Aug 14, 2011 · Viewed 30.4k times · Source

I will be storing a few strings (maybe 10-20). I am not sure if I should use NSUserDefaults to save them, or write them out to a plist. What is considered best practice? NSUserDefaults seems like it is less lines of code, therefore quicker to implement.

I'd like to add that these string values will be added/removed by the user.

Answer

doppioslash picture doppioslash · Aug 14, 2011

I am assuming an array, but it will work with dictionaries too.

Userdefaults, Core Data and Plists can all be read/write but if you use a plist you need to pay attention in what dir you put it. See the plist part down below.

Core Data I think it's way too much overkill, it's just strings. It's supposed to be used when you want to persist more complex objects.

NSUserDefaults:

It's pretty fast and easy to do, though it's supposed to store only user settings. To write them to the userdefaults:

NSArray *stringsArray = [[NSArray alloc] arrayWithObjects: string1, string2, string3, nil];
[[NSUserDefaults standardUserDefaults] setObject:stringsArray forKey:@"MyStrings"];
[[NSUserDefaults standardUserDefaults] synchronize];

To read the from the userdefaults:

NSArray *stringsArray = [[NSUserDefaults standardUserDefaults] objectForKey:@"MyStrings"];

Plist:

If your strings are going to be modified you will need to write and read a plist but you cant't write into your app's resources.

  1. To have a read/write plist first find the documents directory

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *stringsPlistPath = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"Strings.plist"];
    
  2. Create the array (I am assuming the strings are string1, ...)

    NSArray *stringsArray = [[NSArray alloc] arrayWithObjects: string1, string2, string3, nil];
    
  3. Write it to file

    [stringsArray writeToFile:stringsPlistPath atomically:YES];
    

To read the plist:

  1. Find the documents directory

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *stringsPlistPath = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"Strings.plist"];
    
  2. Read it in:

    NSArray *stringsArray = [NSArray arrayWithContentsOfFile:stringsPlistPath];