Add @autoreleasepool as alternative to NSAutoreleasePool object.

objective-c.html.markdown

@@ -28,6 +28,8 @@ int main (int argc, const char * argv[])
 {
     // Create an autorelease pool to manage the memory into the program
     NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
+    // If using automatic reference counting (ARC), use @autoreleasepool instead:
+    @autoreleasepool {
 
     // Use NSLog to print lines to the console
     NSLog(@"Hello World!"); // Print the string "Hello World!"
@@ -268,6 +270,9 @@ int main (int argc, const char * argv[])
     // Clean up the memory you used into your program
     [pool drain];
 
+    // End of @autoreleasepool.
+    }
+    
     // End the program
     return 0;
 }