NSArray *myArray = [NSArrayarrayWithObjects:string1, string2, string3, nil];

　　for (NSString *obj in myArray) {

　　NSLog(@"%@",obj);

　　}

　　for (NSString *obj in [myArrayreverseObjectEnumerator])

　　{

　　NSLog(@"%@",obj);

　　}

　　NSArray *arr1 = [NSArrayarrayWith Objects:@"iPhone", @"iPod",nil];

　　NSDictionary *myDict = [[NSDictionar y alloc] ?dictionaryWithObjectsAndKeys: arr1, @"mobile", arr2, @"computers", nil];

　　for (id key in myDict) {

　　NSLog(@"key: %@, value: %@",

　　? key, [myDictobjectForKey:

　　? key]);

　　}

　　[myDict setObject:string2 forKey:@"media"];

　　NSNotification

　　Notifications provide a handy way for youto pass information between objects in your application without needing a direct reference between them. which contains a name, an object (often the object posting the notification), and an optional dictionary.

　　登记消息、消息处理方法、注销

　　[[NSNotificationCenterdefaultCenter] addObserver:self selector:@selector(doSomething:)

　　? name:@"myNotification"

　　?object:nil];

　　-(void)deallc

　　{

　　[[NSNotificationCenterdefaultCenter] removeObserver:self];

　　[superdealloc];

　　}

　　-(void)doSomething:(NSNotification*)aNote

　　{

　　NSDictionary *myDict = [aNoteobject];

　　NSLog(@”%@”, myDict);

　　}

　　发送消息

　　[[NSNotificationCenterdefaultCenter] postNotificationName:MY_NOTIFICATION?object:myDict];

　　内存管理

　　iOS不支持GC，因此必须手动释放创建的对象[注意是创建者负责释放，像工厂方法的对象不需要调用者释放]

　　[object release];

　　Remember this basic rule of thumb: Any time you call the alloc, copy, or retainmethods on an object, you must at some point later call the release method.