object-c学习笔记：Foundation框架常用类（二）

四、NSDictionary和NSMutableDictionary类

//____________________NSDictionary_________________
        // 创建字典
        NSNumber *number = [NSNumber numberWithInt:100];
        // 初始化一个元素
        NSDictionary *dic = [NSDictionary dictionaryWithObject:number forKey:@"key"];
        NSLog(@"dic : %@", dic);
        // 初始化两个元素
        NSDictionary *dic1 = [NSDictionary dictionaryWithObjectsAndKeys:@"v1", @"k1", @"v2", @"k2", @"v3", @"k3", @"v4", @"k4", @"v5", @"k5", nil];
        NSLog(@"dic1 : %@", dic1);
        // 用一个已存在的dic来初始化另一个dic
        NSDictionary *dic2 = [NSDictionary dictionaryWithDictionary:dic];
        NSLog(@"dic2 : %@", dic2);
        // 取字典的数量
        int count = [dic1 count];
        NSLog(@"count : %d", count);
        // 根据指定的key取value
        NSString *value = [dic1 valueForKey:@"k2"];
        NSLog(@"value for key k2 : %@", value);
        // 获取所有键的集合
        NSArray *keys = [dic1 allKeys];
        NSArray *values = [dic1 allValues];
        NSLog(@"keys : %@", keys);
        NSLog(@"values : %@", values);
        
        ///////////////////////////////////////////////////
        // 可变字典     继承自NSDictionary，所以上面NSDictionary的方法它都有
        // 初始化一个空的可变字典
        NSMutableDictionary *mutableDic = [NSMutableDictionary dictionary];
        NSLog(@"mutableDic = %@", mutableDic);
        // 用一个元素初始化
        NSMutableDictionary *mutableDic2 = [NSMutableDictionary dictionaryWithObject:@"value" forKey:@"key"];
        NSLog(@"mutableDic2 : %@", mutableDic2);
        // 用多个元素初始化
        NSMutableDictionary *mutableDic3 = [NSMutableDictionary dictionaryWithObjectsAndKeys:@"v1", @"k1", @"v2", @"k2", @"v3", @"k3", @"v4", @"k4", @"v5", @"k5", nil];
        NSLog(@"mutableDic3 : %@", mutableDic3);
        // 向字典中添加整个字典对象
        [mutableDic3 addEntriesFromDictionary:mutableDic2];
        NSLog(@"mutableDic3 : %@", mutableDic3);
        // 向字典中添加一对新的key和value
        [mutableDic3 setValue:@"v6" forKey:@"k6"];
        NSLog(@"mutableDic3 : %@", mutableDic3);
        // 将字典1设置成和字典2的内容一样   注意，字典1原先的内容会被覆盖掉
        [mutableDic2 setDictionary:mutableDic3];
        NSLog(@"mutableDic2 : %@", mutableDic2);
        // 根据key删除键值对
        [mutableDic2 removeObjectForKey:@"key"];
        NSLog(@"mutableDic2 : %@", mutableDic2);
        
        /////////////////////////////////////////////////////
        // 字典的遍历
        
        // 效率低法
        NSArray *keys1 = [mutableDic2 allKeys];
        for (int i = 0; i < [mutableDic2 count]; i++) {
            NSString *key = [keys1 objectAtIndex:i];
            NSString *value = [mutableDic2 valueForKey:key];
            NSLog(@"key = %@  :   value = %@", key, value);
        }
        
        NSLog(@"----------------------------");
        // 高效
        for (id key in mutableDic2) {
            id value = [mutableDic2 objectForKey:key];
            
            NSLog(@"%@ : %@", key, value);
        }
        
        // 用枚举类型枚举
        NSEnumerator *enumerator = [mutableDic2 keyEnumerator];
        id key;
        while (key = [enumerator nextObject]) {
            NSLog(@"%@  --->  %@", key, [mutableDic2 objectForKey:key]);
        }

五、NSSet和NSMutableSet类

//____________________NSSet________________________
        // 集合的创建
        NSSet *set1 = [NSSet setWithObjects:@"1", @"2", nil];
        NSLog(@"set1 : %@", set1);
        NSSet *set2 = [[NSSet alloc] initWithObjects:@"3", @"4", @"2", nil];
        NSLog(@"set2 : %@", set2);
        NSArray *array = [NSArray arrayWithObjects:@"8", @"9", nil];
        NSSet *set3 = [NSSet setWithArray:array];
        NSLog(@"set3 : %@", set3);
        NSSet *set4 = [NSSet setWithSet:set1];
        NSLog(@"set4 : %@", set4);
        //取集合的元素个数
        int count = [set2 count];
        NSLog(@"count : %d", count);
        // 将集合入一个数组中
        NSArray *array2 = [set2 allObjects];
        NSLog(@"array2 : %@", array2);
        // 取任意一个元素
        id object = [set2 anyObject];
        NSLog(@"object : %@", object);
        // 是否包含某个对象
        BOOL isContain = [set2 containsObject:@"2"];
        NSLog(@"isContain : %d", isContain);
        // 判断两个set是否存在交集
        BOOL isInter = [set1 intersectsSet:set2];
        NSLog(@"isInter : %d", isInter);
        // 判断两个集合中的元素是否完全相同
        BOOL isEqual = [set1 isEqualToSet:set2];
        NSLog(@"isEqual : %d", isEqual);
        // 判断一个集合是否是另一个集合的子集
        BOOL isSub = [set1 isSubsetOfSet:set2];
        NSLog(@"isSub : %d", isSub);
        // 通过已有的两个集合创建一个新的集合
        NSSet *set7 = [NSSet setWithObjects:@"2", nil];
        NSSet *set8 = [NSSet setWithObjects:@"3", nil];
        NSSet *set9 = [set7 setByAddingObjectsFromSet:set8];
        NSLog(@"set9 : %@", set9);
        
        
        //////////////////////////////////
        // NSMutableSet 继承自NSSet
        // 创建可变集合
        NSMutableSet *mutableSet1 = [NSMutableSet setWithObjects:@"2", @"1", nil];
        NSMutableSet *mutableSet2 = [NSMutableSet setWithObjects:@"3", @"1", nil];
        // 集合1减去集合2
        [mutableSet1 minusSet:mutableSet2];
        NSLog(@"mutableSet1 : %@", mutableSet1);
        
        // 集合2和集合1的交集
        [mutableSet1 intersectSet:mutableSet2];
        NSLog(@"mutableSet1 : %@", mutableSet1);
        
        // 并集
        [mutableSet1 unionSet:mutableSet2];
        NSLog(@"mutableSet1 : %@", mutableSet1);
        
        // 将集合一设置为集合二的内容
        [mutableSet1 setSet:mutableSet2];
        NSLog(@"mutableSet1 : %@", mutableSet1);
        
        // 删除指定的对象
        [mutableSet1 removeObject:@"1"];
        NSLog(@"mutableSet1 : %@", mutableSet1);