Object-C-NSDictionary

標籤：

儲存物件都必須是id(物件類型)不能使基礎類型

NSDictionary *scores=[[NSDictionary alloc]initWithObjectsAndKeys:@"89",@"english",@"70",@"computer",nil];

*scores=[[NSDictionary alloc]initWithObjectsAndKeys:[NSNumber numberWithInt:89],@"english"];

scores=[NSDictionary dictionaryWithObjectsAndKeys:]用法與initWithObjectsAndKeys;

NSNumber *englishScore=[scores objectForKey:@"english"];

 

集合的遍曆

方法一

for(NSString *key int socres)

{

    // 通過每個元素的key訪問value

    NSLog(@"%@:%d",key,[[score objetForKey:key] intValue]);

}

方法二

[socres enumerateKeysAndObjectsUsingBloc:^(id key, id obj,BOOL *stop)

{

   NSNumber *num=(NSNumber *)obj;

    NSLog(@"%@:%d",key,[num intValue]);

}

方法三

NSArray *keysArray = [scores allKeys];

for(int i=0; i<[scores count]; i++)

{

     NSLog(@"%@:%d",[keysArray objectAtIndex:i);

NSLog(@"")----;

}

字典排序

NSArray *keysArray=[scores keysSortedByValueUsingSelector:@selector(compare:)];

 

Object-C-NSDictionary