NSArray NSDictionary一些用法

    //从字符串分割到数组－ componentsSeparatedByString:
    NSString *str = ［NSString alloc] initWithString:@"a,b,c,d"];
    NSLog(@"str:%@",str);    
    NSArray *array = [str componentsSeparatedByString:@","];
    NSLog(@"array:%@",array);
    [str release]; 

    //从数组合并元素到字符串- componentsJoinedByString:
    NSArray *array = ［NSArray alloc] initWithObjects:@"One",@"a",@"b",@"c",nil];
    NSString *string = [array componentsJoinedByString:@","];
    NSLog(@"string:%@",string);

   //给数组分配容量
   NSArray *array = [NSMutableArray arrayWithCapacity:20];

   //在数组末尾添加对象

   NSMutableArray *array = [NSMutableArray arrayWithObjects:@"a",@"b",@"c",nil];
   [array addObject:@"d"];
   NSLog(@"array:%@",array);

   //删除数组中指定索引处对象
   NSMutableArray *array = [NSMutableArray arrayWithObjects:@"a",@"b",@"c",nil];
   [array removeObjectAtIndex:1];
   NSLog(@"array:%@",array);

    //数组枚举
    NSMutableArray *array = [NSMutableArray arrayWithObjects: @"a",@"b",@"c",nil];
    NSEnumerator *enumerator;
    enumerator = [array objectEnumerator]; 
    id enum;
    while (enum = [enumerator nextObject]) {
        NSLog(@"enum:%@",enum);
 8      }

    //reverseObjectEnumerator;从后向前
    NSMutableArray *array = [NSMutableArray arrayWithObjects:@"a",@"b",@"c",nil];
    NSEnumerator *enumerator;
    enumerator = [array reverseObjectEnumerator];
    id object;
    while (object = [enumerator nextObject]) {
 7         NSLog(@"object:%@",object);
 8     }

    //快速枚举
    NSMutableArray *array = [NSMutableArray arrayWithObjects:
    @"a",@"b",@"c",nil];
    for(NSString *string in array)
    {
        NSLog(@"string:%@",string);
    }

1    //创建字典
2    NSDictionary *dictionary = ［NSDictionary alloc] initWithObjectsAndKeys:@"a",@"b",@"c",nil];
3    NSString *string = [dictionary objectForKey:@"One"];
4    NSLog(@"string:%@",string);
5    NSLog(@"dictionary:%@",dictionary);
6    [dictionary release];

    //创建可变字典
    NSMutableDictionary *dictionary = [NSMutableDictionary dictionary];
    //添加字典
    [dictionary setObject:@"One" forKey:@"1"];
    [dictionary setObject:@"Two" forKey:@"2"];
    [dictionary setObject:@"Three" forKey:@"3"];
    [dictionary setObject:@"Four" forKey:@"4"];
    NSLog(@"dictionary:%@",dictionary);

    //删除指定的字典
    [dictionary removeObjectForKey:@"3"];
    NSLog(@"dictionary:%@",dictionary);

    //NSDictionary 初始化
    NSDictionary *dictionary = [NSDictionary dictionaryWithObjectsAndKeys:@"a", @"b", @"c", nil];
    //NSDictionary 个数
    NSLog(@"dictionary count: %ld", [dictionary count]);

    //NSDictionary 枚举keys/values 
    NSEnumerator *enum = [dictionary objectEnumerator];
    for (NSObject *enum in enum) {
        NSLog(@"enum: %@", enum);
     }


    NSDictionary *dictionary = [NSDictionary dictionaryWithObjectsAndKeys:@"a",@"b",@"c", nil];
    
    //得到词典的数量
    int count = [dictionary count];
    NSLog(@"词典的数量为： %d",count);
    
    //得到词典中所有KEY值
    NSEnumerator * enumeratorKey = [dictionary keyEnumerator];
    
    //快速枚举遍历所有KEY的值
    for (NSObject *object in enumeratorKey) {
        NSLog(@"遍历KEY的值: %@",object);
    }
    
    //得到词典中所有Value值
     NSEnumerator * enumeratorValue = [dictionary objectEnumerator];
    
    //快速枚举遍历所有Value的值
    for (NSObject *object in enumeratorValue) {
        NSLog(@"遍历Value的值: %@",object);
    }
    
    //通过KEY找到value
    NSObject *object = [dictionary objectForKey:@"a"];
    
    if (object != nil) {
        NSLog(@"通过KEY找到的value是: %@",object);
    }