集合(set)是一组单值对象，它可以是固定的(NSSet)、也可以是可变的(NSMutableSet)。集合可以比较、计算交集、并集，可变集合还可以有查找、添加、删除。
二、常用方法
#import <Foundation/Foundation.h>
int main (int argc, char *argv[])
{
NSAutoreleasePool*pool=[[NSAutoreleasePool alloc]init];
//集合比较、修改
NSSet *set1=[NSSet setWithObjects:@"s1",@"s2",@"s3",@"s4",nil];
NSMutableSet *set2=[NSMutableSet setWithObjects:@"s1",@"s2",@"s3",@"s4",nil];
NSLog(@"List set1");
for (NSString *element in set1) {
NSLog(@"%@",element);
}
if ([set1 isEqualToSet:set2]) {
NSLog(@"set1 is equal to set set2");
} else {
NSLog(@"set1 is not equal to set set2");
}
if ([set1 containsObject:@"s1"]) {
NSLog(@"set1 contains s1");
} else {
NSLog(@"set1 not contains s1");
}
[set2 addObject:@"s5"];
[set2 removeObject:@"s3"];
NSLog(@"List set2");
for (NSString *element in set2) {
NSLog(@"%@",element);
}
//集合交集、并集
NSMutableSet *set3;
set3=[NSMutableSet setWithObjects:@"s1",@"s3",@"s5",nil];
[set3 intersectSet:set1];
NSLog(@"135 intersectSet 1234");
for (NSString *element in set3) {
NSLog(@"%@",element);
}
set3=[NSMutableSet setWithObjects:@"s1",@"s3",@"s5",nil];
[set3 unionSet:set1];
NSLog(@"135 unionSet 1234");
for (NSString *element in set3) {
NSLog(@"%@",element);
}
[pool drain];
return 0;
}
setWithObjects创建包含给定的对象列表的集合
+ (id)setWithObjects:(id)firstObj ...
isEqualToSet比较两个集合是否相等
- (BOOL)isEqualToSet:(NSSet *)otherSet
containsObject判断给定的对象是否在集合中
- (BOOL)containsObject:(id)anObject
addObject给集合添加一个对象，如果已有这个对象则不会添加
- (void)addObject:(id)object
removeObject删除集合中给定的对象
- (void)removeObject:(id)anObject
intersectSet取两个集合的交集，如果接收集合中的成员不是给定集合的成员，则从接受集合中删除这个成员。
- (void)intersectSet:(NSSet *)otherSet
unionSet取两个集合的并集，如果给定集合中的成员不是接收集合的成员，则将这个成员添加到接收集合中。
- (void)unionSet:(NSSet *)otherSet
三、NSSet的全部方法
Creating a Set
+ set
+ setWithArray:
+ setWithObject:
+ setWithObjects:
+ setWithObjects:count:
+ setWithSet:
– setByAddingObject:
– setByAddingObjectsFromSet:
– setByAddingObjectsFromArray:
Initializing a Set
– initWithArray:
– initWithObjects:
– initWithObjects:count:
– initWithSet:
– initWithSet:copyItems:
Counting Entries
– count
Accessing Set Members
– allObjects
– anyObject
– containsObject:
– filteredSetUsingPredicate:
– makeObjectsPerformSelector:
– makeObjectsPerformSelector:withObject:
– member:
– objectEnumerator
– enumerateObjectsUsingBlock:
– enumerateObjectsWithOptions:usingBlock:
– objectsPassingTest:
– objectsWithOptions:passingTest:
Comparing Sets
– isSubsetOfSet:
– intersectsSet:
– isEqualToSet:
– valueForKey:
– setValue:forKey:
Creating a Sorted Array
– sortedArrayUsingDescriptors:
Key-Value Observing
– addObserver:forKeyPath:options:context:
– removeObserver:forKeyPath:context:
– removeObserver:forKeyPath:
Describing a Set
– description
– descriptionWithLocale:
四、NSMutableSet的全部方法
Creating a Mutable Set
+ setWithCapacity:
– initWithCapacity:
Adding and Removing Entries
– addObject:
– filterUsingPredicate:
– removeObject:
– removeAllObjects
– addObjectsFromArray:
Combining and Recombining Sets
– unionSet:
– minusSet:
– intersectSet:
– setSet: