OC学习笔记17--Foundation集合类之NSSet与NSDictionary

#import   

void testSet();
void testDictionary();
  
int main(int argc, const char * argv[])  
{    
	NSAutoreleasePool *pool=[[NSAutoreleasePool alloc] init];
	
	testSet();
	NSLog(@"\n\n------------------------------\n\n");
	testDictionary();
	
	[pool drain];
	return 0;
} 

void testDictionary()
{
	// 此种方式创建集合对象，最后都要以nil结尾
	NSMutableDictionary *mdict=[NSMutableDictionary dictionaryWithObjectsAndKeys:
		@"James",@"name",
		[NSNumber numberWithInteger:20],@"age",
		@"1568956556",@"phoneNo",nil];
	[mdict setObject:[NSNumber numberWithFloat:66.6] forKey:@"weight"];
	[mdict removeObjectForKey:@"phoneNo"];
	// 根据key取value，没找到返回空
	NSLog(@"name=%@,age=%d,phontNo=%@,weight=%.2f",
	[mdict objectForKey:@"name"],
	[[mdict objectForKey:@"age"] intValue],
	[mdict objectForKey:@"phoneNo"],
	[[mdict objectForKey:@"weight"] doubleValue]);
	
	// @方式快速创建出来的都是不可变对象
	NSDictionary *dict=@{
		@"name":@"Bruce",
		@"age":[NSNumber numberWithLong:28],
		@"phoneNo":@"1868955656",
		@"weight":[NSNumber numberWithDouble:72.2]};	
	NSLog(@"dict=%@",dict);
	
	// for循环方式遍历字典
	NSArray *keys=[mdict allKeys];
	int i;
	for(i=0;i<[mdict count];i++)
	{	
		id key = [keys objectAtIndex:i];
		id val = [mdict objectForKey:key];
		NSLog(@"%@=%@",key,val);
	}

	// 字典自身的利用block遍历方法
	[dict enumerateKeysAndObjectsUsingBlock:
	^(id key,id obj,BOOL *stop)
	{
		NSLog(@"%@=%@",key,obj);
	}];
	
}

void testSet()
{
	NSSet *set = [NSSet setWithObjects:@"123",@"123",@"222",
	[[[NSObject alloc] init] autorelease],@"333",@"444",@"222",nil];
	//Set中元素是无序且唯一
	NSLog(@"setCount=%d andSet=%@",[set count],set);
	// anyObject多次调用返回同一个值，但这个值是不确定的
	NSLog(@"[set anyObject]=%@",[set anyObject]);
	NSLog(@"[set anyObject]=%@",[set anyObject]);
	NSLog(@"[set anyObject]=%@",[set anyObject]);
	
	NSMutableSet *mset=[NSMutableSet set];
	[mset addObjectsFromArray:[NSArray arrayWithObjects:
	@"123",@"123",@"222",[[[NSObject alloc] init] autorelease],
	@"333",@"444",@"222",nil]];
	[mset removeObject:@"222"];
	NSLog(@"msetCount=%d and mset=%@",[mset count],mset);
}

NSSet：
特点：
无序，唯一，仅限存非空的OC对象，本身初始化后内容不可变,其子类NSMutableSet为可变；
常用方法：
+(id)setWithObjects:(id)obj,...,nil;
-(NSUInteger)count;
// 返回任意的一个对象
-(id)anyObject;
NSMutableSet:
常用方法：
-(void)addObjectsFromArray:(NSArray *)from;
-(void)removeObject:(id)obj;




NSDictionary:
特点：
类似java中Map，键值对形式保存数据，无序，key唯一，key值仅限非空OC对象，
value值仅限OC对象，本身初始化后内容不可变，子类NSMutableDictionary可变；
常用方法：
+(id)dictionaryWithObjects:(NSArray *)objs forKeys:(NSArray *)keys;
//动态参数顺序为 val,key,val,key,...,nil
+(id)dictionaryWithObjectsAndKeys:(id)obj,...,nil;
@快速创建方式： //返回不可变的字典
@{key1:value1,key2:value2,...};

// 根据key获取值，便捷形式为 dict[key]
-(id)objectForKey:(id)key;
//获取保存的键值对个数
-(NSUInteger)count;
//返回所有key的集合
-(NSArray *)allKeys;
//利用block遍历
-(void)enumerateKeysAndObjectsUsingBlock:^(id key,id obj,BOOL *stop)block;

NSMutableDictionary:
-(void)setObject:(id)obj forKey:(id)key;
-(void)removeObjectForKey:(id)key;