Question

I had created a project using base sdk 5.0 in xcode 4.2. While creating the project, I had not checked all 3 options that are displayed, when we create the new project on iOS 5.0, namely. storyboard, use ARC and include unit tests. After writing my code, I want to run this on xcode 3.2.5/ iOS 4.2, but it gives an error because iOS 5 uses @autoreleasepool instead of NSAutoreleasePool. How will I run it on iOS4.2

Answer 1

How about using the old main.m?

#import <UIKit/UIKit.h>

int main(int argc, char *argv[])
{
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
    int retVal = UIApplicationMain(argc, argv, nil, nil);
    [pool release];
    return retVal;
}

Another thing. “storyboards” and “ARC” are only supported in iOS 5. So this will be a problem too if you want to run this in iOS4.

summary:
if u want backward compatibility write your program on the lowest version you want to support and it will be fine. use old main.m, retain instead of strong and no storyboards or ARC and it works on iOS >= 4.