问弱指针与强指针在xcode 5中的行为略有不同。

EN

@interface settingsViewController ()
@property (weak,nonatomic) Reachability *reachable;
@end

//called on click
/ Checks if we have an internet connection or not
- (void)testInternetConnection
{
    self.reachable= [Reachability reachabilityWithHostname:@"www.google.com"];
if (self.reachable)
{
    NSLog(@"reachability created");

}
    else
    {
        NSLog(@"NO OBJECT");
    }
//do more stuff.....
}

#pragma mark - class constructor methods
+(Reachability*)reachabilityWithHostname:(NSString*)hostname
{
    SCNetworkReachabilityRef ref = SCNetworkReachabilityCreateWithName(NULL, [hostname UTF8String]);
    NSLog(@"init1");
    if (ref) 
    {
        NSLog(@"init2");
        id reachability = [[self alloc] initWithReachabilityRef:ref];

#if __has_feature(objc_arc)
        NSLog(@"init with arc");

        return reachability;
#else
        NSLog(@"init no arc");

        return [reachability autorelease];
#endif

    }
    NSLog(@"cannot init");

    return nil;
}