NSSet 集合

• NSArray 自然順序
• NSSet是無序的
• 注意:這個是最為重要的功能 NSSet 中不能夠儲存重複的資料,可以用它來去除重複的值

NSString * str1 = @"one";
NSString * str2 = @"two";
NSString * str3 = @"three";
NSSet * set = [[NSSet alloc] initWithObjects:str1,str2,str3,str1, nil];
NSLog(@"set %@",set);

//count
NSLog(@"count %ld",set.count);

OOL isContains =  [set containsObject:str1];
if
 
 (isContains)
{
    NSLog(@"YES");
}
else
{
    NSLog(@"NO");
}

遍歷

NSEnumerator * enumerator = [set objectEnumerator];
NSString * value;
while (value = [enumerator nextObject]) {
    NSLog(@"value %@",value);
}

NSMutableSet 可變集合

NSString * str1 = @"one";
NSString * str2 = @"two";

//1 建立一個可變集合
 

NSMutableSet * muSet = [[NSMutableSet alloc] init];

//2.增加值
[muSet addObject:str1];
[muSet addObject:str2];

NSLog(@"muSet %@",muSet);

//3.刪除
[muSet removeObject:str1];

NSLog(@"muSet %@",muSet);

//4.刪除所有
[muSet removeAllObjects];

NSLog(@"muSet %@",muSet);

//5.遍歷
NSEnumerator * en = [muSet objectEnumerator];
NSString
 
 * value;
while (value = [en nextObject]) {
    NSLog(@"value %@",value);
}