第八天 NSSet集合

NSSet集合的好处有两点第一就是元素是不可以重复2是无序的

eg

NSArray *array=@[@"one",@"two",@"three"];

NSLog(@"%@",array);

NSSet *set=[NSSet setWithArray:array];

NSLog(@"%@",set);

NSSet 的创建

NSSet *set=[NSSet setWithObject :@"one",@"two",@"three",nil];

NSLog(@"%@",set);

另外一种创建

NSSet *set2=[NSSet setWithSet:set1];

NSLog(@"%@",se2);

使用另外一个数组创建

NSArray *array=@[@"one",@"two",@"trhee"];

NSSet *set3=[NSSet setWithArray:array];

NSLog(@"%@",set3);

枚举遍历

NSSet *set1=[NSSet setWithObjects:@"one",@"two",@"three"];

NSEnumerator *e=[set1 objectEnumerator];

NSString *s;

while((s=[e nextObject])!=nil)

{

NSLog(@"%@",s);

判断某个对象中是否有其他成员

NSSet *set1=[NSSet setWithObjects:@"one",@"two",@"three"];

NSSting *e=[set1 member:@"one"];

NSLog(@"%@",e);

 

}

获取集合中的任意一个对象

NSSet *set1=[NSSet setWithObjects :@"one",@"two",@"three"];

NSString *e=[set1 anyObject];

NSLog(@"%@",e);

判断两个Set是否相等

NSSet *set1=[NSSet setWithObjects:@"one",@"two",@"one"];

NSSet *set2=[NSSet setWithObjects:@"one",@"two",@"one"];

BOOL r=[set1 isEqualToSet:set2];

NSLog(@"%@",r==1?@"YES":@"NO");

//判断两个集合是否有交集

NSSet *set1=[NSSet setWithObjects:@"one",@"two",@"one",@"100",nil];

NSSet *set2=[NSSet setWithObjects:@"one",@"two",@"one",@"200",nil];

BOOL r=[set1 isSubsetOfSet:set2];

NSLog(@"%@",r==1?@"YES":@"NO");