StackOverflow2013

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copied!<p>First, you might consider using a class to hold your inner array's strings, or loading it from a plist file (in which it is easy to make an 2d array of strings).</p> <p>For direct declarations, you have a couple of options. If you want to use an NSArray, you'll have to manually create the structure like this:</p> <pre><code>NSMutableArray *strings = [NSMutableArray array]; for(int i = 0; i < DESIRED_MAJOR_SIZE; i++) { [strings addObject: [NSMutableArray arrayWithObject:@"" count:DESIRED_MINOR_SIZE]]; } </code></pre> <p>Or, using array literals, you can get an <em>immutable</em> version like this:</p> <pre><code>NSArray *strings = @[ @[ @"A", @"B", @"C" ], @[ @"D", @"E", @"F" ], @[ @"G", @"H", @"I" ] ] </code></pre> <p>You can then use it like this:</p> <pre><code>NSString *s = [[strings objectAtIndex:i] objectAtIndex:j]; </code></pre> <p>This is somewhat awkward to initialize, but it is the way to go if you want to use the NSArray methods.</p> <p>An alternative is to use C arrays:</p> <pre><code>NSString *strings[MAJOR_SIZE][MINOR_SIZE] = {0}; // all start as nil </code></pre> <p>And then use it like this:</p> <pre><code>NSString *s = strings[i][j]; </code></pre> <p>This is less awkward, but you have to be careful to <em>retain/copy</em> and <em>release</em> values as you put them in to and remove them from the array. (Unless you're using ARC, of course!) NSArray would do this for you but with C-style arrays, you need to do something like this to replace an array:</p> <pre><code>[strings[i][j] release]; strings[i][j] = [newString retain]; </code></pre> <p>The other difference is that you can put nil in the C-style array, but not the NSArrays - you need to use NSNull for that. Also take a look at Stack Overflow question <em><a href="https://stackoverflow.com/questions/329977/cocoa-memory-management-with-nsstring">Cocoa: Memory management with NSString</a></em> for more about NSString memory management.</p>

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