langs a-z

Task/Arrays/Objective-C/arrays.m

@@ -0,0 +1,23 @@
+// NSArrays are ordered collections of NSObject subclasses only.
+
+// Create an array of NSString objects.
+NSArray *firstArray = [[NSArray alloc] initWithObjects:@"Hewey", @"Louie", @"Dewey", nil];
+
+// NSArrays are immutable; it does have a mutable subclass, however - NSMutableArray.
+// Let's instantiate one with a mutable copy of our array.
+// We can do this by sending our first array a -mutableCopy message.
+NSMutableArray *secondArray = [firstArray mutableCopy];
+
+// Replace Louie with Launchpad McQuack.
+[secondArray replaceObjectAtIndex:1 withObject:@"Launchpad"];
+
+// Display the first object in the array.
+NSLog(@"%@", [secondArray objectAtIndex:0]);
+
+// In non-ARC or non-GC environments, retained objects must be released later.
+[firstArray release];
+[secondArray release];
+
+// There is also a modern syntax which allows convenient creation of autoreleased immutable arrays.
+// No nil termination is then needed.
+NSArray *thirdArray = @[ @"Hewey", @"Louie", @"Dewey", @1, @2, @3 ];