wangzi11322的专栏

NSSet和NSArray的对比

/* NSSet和NSArray的对比 1> 共同点 * 都是集合，都能存放多个OC对象 * 只能存放OC对象，不能存放非OC对象类型（基本数据类型：int、char、float等，，结构体，枚举） * 本身都不可变，都有一个可变的子类 2> 不同点 * NSArray有顺序，NSSet没有顺序 */

重点内容

___log(NSSet* set1);static void ___log(NSSet* set1){NSMutableString * str = [NSMutableString stringWithFormat:@”NSSet{“];for (id item in set1) {[str appendFormat:@”%@,”,item];}//删除最后一个逗号NSRange rng ={str.length-1,1};[str deleteCharactersInRange:rng];[str appendString:@”}”];NSLog(@”%@”,str);}

演练set判断重复的依

: * name;@property NSNumber* age;@property (nonatomic, strong) NSString * week;+ (instancetype) personWithName:(NSString*) name withAge:(NSNumber*)age;@end#Person@synthesize name,age;+ (instancetype)personWithName:(NSString *)name withAge:(NSNumber *)age{Person* person=[[Person alloc]init];person.name=name;person.age=age;return person;}/** * 重写hash方法 */- (NSUInteger) hash{NSLog(@”访问了hash”);NSDate* date=[NSDate new];return date.timeIntervalSinceReferenceDate;}/** * 重写isEqual方法 */- (BOOL)isEqual:(id)object{return YES;}@endint main(int argc, const char * argv[]) {@autoreleasepool {//演练set判断重复的依据Person* jobs=[Person personWithName:@”steven jobs” withAge:[NSNumber numberWithInt:56]];Person* cook=[Person personWithName:@”david cook” withAge:[NSNumber numberWithInt:54]];Person* cook2=[Person personWithName:@”david cook” withAge:[NSNumber numberWithInt:54]];NSSet* personSet =[NSSet setWithObjects:jobs,cook,cook2, nil];NSLog(@”personSet_count:%lu”,personSet.count);

集合的创建

NSLog(@”*************************** 集合的创建 **************************”);NSSet *s1 = [NSSet setWithObjects:@”tom”,@”rose”, @”jack”,@”lily”,nil];NSString *str = [s1 anyObject];// 随机拿出一个元素NSLog(@”随机取出的元素为:%@”, str);//集合里只能存放OC对象，不能存放非OC对象类型NSSet* set=[NSSet setWithObjects:@”rose”,@”jack”,[NSNumber numberWithInt:4],nil];NSLog(@”set的长度为:%lu”,[set count]);for (id item in set) {NSLog(@”item:%@”,item);}

集合的遍历

NSLog(@”*************************** 集合的遍历 **************************”);NSArray* arr=[NSArray arrayWithObjects:@”中国”,@”日本”, @”朝鲜”,@”韩国”,nil];NSSet* set1=[NSSet setWithArray:arr];NSLog(@”%2@”,set1.className);NSArray* arr2=[set1 allObjects];for (NSString* item in arr2) {NSLog(@”%@”,item);}

判断交集

NSLog(@”**************************** 判断交集 ***************************”);NSSet* intersect=[NSSet setWithObjects:@”中国”,@”日本”, nil];if ([set1 intersectsSet:intersect]) {NSLog(@”intersect是set1的交集”);}

可变集合操作

NSLog(@”*************************** 可变集合操作 *************************”);//从现有的set转换为MutableSet,获得一份可变集合的拷贝NSMutableSet* mset=[intersect mutableCopy];NSLog(@”mset:%@”,mset.className);//添加对象[mset addObject:@”新加坡”];NSLog(@”添加对象后的集合为:%@”,mset);//删除对象[mset removeObject:@”日本”];NSLog(@”删除对象后的集合为:%@”,mset);//求并集[mset unionSet:set1];___log(mset);NSLog(@”并集为:%@”,mset);//求补集[mset minusSet:intersect];___log(mset);NSLog(@”补集为:%@”,mset);//求交集[mset intersectsSet:set1];___log(mset);NSLog(@”交集为:%@”,mset);

NSCountedSet

NSLog(@”*************************** NSCountedSet **************************”);* sourStr=@”abc abc 123 ab cd cd”;NSArray* strArr=[sourStr componentsSeparatedByString:@” “];NSCountedSet* csset=[NSCountedSet setWithArray:strArr];NSUInteger count=[csset countForObject:@”abc”];NSLog(@”求得的abc的重复数为:%lu”,count);

属于自己的不要放弃，已经失去的留作回忆。