NSSet和NSMutableSet的常用方法

标签（空格分隔）： 常用方法

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一、NSSet的常用方法

• 不可变集

1、创建

- (instancetype)initWithObjects:(ObjectType)firstObj, …

NSSet *set = [[NSSet alloc] initWithObjects:@"1",@"2",@"3", nil];NSLog(@"set = %@",set);

运行结果

2016-02-27 14:48:37.805 OCLesson5_NSSet[1744:142587] set = {(    1,    2,    3)}

2、元素个数

NSLog(@"count = %ld",[set count]);

运行结果

2016-02-27 14:48:37.806 OCLesson5_NSSet[1744:142587] s1 = 1

3、将set中的所有元素放到数组中

@property (readonly, copy) NSArray *allObjects;

NSArray *setArr = [set allObjects];NSLog(@"setArr = %@",setArr);

运行结果

2016-02-27 14:48:37.806 OCLesson5_NSSet[1744:142587] setArr = (    1,    2,    3)

4、任意取出一个元素

- (nullable ObjectType)anyObject

NSString *s1 = [set anyObject];NSLog(@"s1 = %@",s1);

运行结果

2016-02-27 14:48:37.806 OCLesson5_NSSet[1744:142587] s1 = 1

5、判断集set中是否包含给定对象

- (BOOL)containsObject:(ObjectType)anObject;

BOOL b = [set containsObject:@"1"];NSLog(@"b = %d",b);

运行结果

2016-02-27 14:48:37.806 OCLesson5_NSSet[1744:142587] b = 1

二、NSMutableSet

• 可变集

1、创建

NSMutableSet *mset = [[NSMutableSet alloc] initWithCapacity:10];

2、添加元素

[mset addObject:@"1"];[mset addObject:@"2"];[mset addObject:@"3"];NSLog(@"mset = %@",mset);

运行结果

2016-02-27 14:48:37.806 OCLesson5_NSSet[1744:142587] mset = {(    3,    1,    2)}

3、删除元素

[mset removeObject:@"2"];NSLog(@"mset = %@",mset);

运行结果

2016-02-27 14:48:37.807 OCLesson5_NSSet[1744:142587] mset = {(    3,    1)}

4、删除全部

[mset removeAllObjects];NSLog(@"mset = %@",mset);

运行结果

2016-02-27 14:48:37.807 OCLesson5_NSSet[1744:142587] mset = {()}Program ended with exit code: 0