OC语言 - 字典 | 集合

NSDictionary

1 - 字典的特性：① 只能存储对象；② 无序存储；③ key 唯一性

2 - 代码示例

① 如何使用 NSDictionary

    // 方式一：创建
    NSDictionary *dic01 = [[NSDictionary alloc] initWithObjectsAndKeys:@"Hazell",@"name",@"female",@"sex",@"26",@"age", nil];
    NSLog(@"%@",dic01);
    
    // 方式二：创建
    NSDictionary *dic02 = [NSDictionary dictionaryWithObjectsAndKeys:@"Jane",@"name",@"female",@"sex",@"22",@"age", nil];
    NSLog(@"%@",dic02);

    // 方式三：可以配合数组实现字典的创建
    NSArray *values01 = [NSArray arrayWithObjects:@"Solina",@"female",@"18", nil];
    NSArray *keys01 = [NSArray arrayWithObjects:@"name",@"sex",@"age", nil];
    NSDictionary *dic03 = [NSDictionary dictionaryWithObjects:values01 forKeys:keys01];
    NSLog(@"%@",dic03);

    // 键值对个数
    NSLog(@"%ld",[dic03 count]);
    // 通过 key 来索引数据
    NSString *name01 = [dic03 objectForKey:@"name"];
    // 获取字典中所有的 key
    NSArray *allkeys01 = [dic03 allKeys];
    // 获取字典中所有的值
    NSArray *allvalues01 = [dic03 allValues];

② 遍历字典

    // 一般情况下直接遍历字典
    NSDictionary *dic04 = [NSDictionary dictionaryWithObjectsAndKeys:@"Jack",@"name",@"male",@"sex",@"21",@"age", nil];
    NSLog(@"%@",dic04);
    
    // 遍历字典
    for (int i = 0; i < [dic04 count]; i ++) {
        // 方式一
        NSString *key_i = [[dic04 allKeys] objectAtIndex:i];
        NSString *value_i = [dic04 objectForKey:key_i];// 通过 key 索引数据
        NSLog(@"%@",value_i);

        //方式二（不推荐）
        NSString *value_j = [[dic04 allValues] objectAtIndex:i];
        NSLog(@"%@",value_j);
    }


    // 数组嵌套字典
    NSDictionary *stuDic01 = [NSDictionary dictionaryWithObjectsAndKeys:@"Hillary",@"name",@"female",@"sex",@"18",@"age", nil];
    NSDictionary *stuDic02 = [NSDictionary dictionaryWithObjectsAndKeys:@"Lee",@"name",@"male",@"sex",@"19",@"age", nil];
    NSArray *arr05 = [NSArray arrayWithObjects:stuDic01,stuDic02, nil];
    NSLog(@"%@",arr05);
    // 方式一
    for (int i =0; i < [arr05 count]; i ++) {

        NSDictionary *dic08_i = [arr05 objectAtIndex:i];
        for (int j = 0; j < [dic08_i count]; j ++) {

            NSString *key03_j = [[dic08_i allKeys] objectAtIndex:j];
            NSString *value03_j = [dic08_i objectForKey:key03_j];
            NSLog(@"%@",value03_j);
        }
    }

    // 方式二
    for(int i = 0; i < [arr05 count]; i ++){

        NSDictionary *dic09_i = [arr05 objectAtIndex:i];
        NSArray *arrayValues02 = [dic09_i allValues];
        for (int j = 0; j < [arrayValues02 count]; j ++) {

            NSString *stringValue_j =  [arrayValues02 objectAtIndex:j];
            NSLog(@"%@",stringValue_j);
        }
    }


    // 字典嵌套数组
    NSArray *firstArray05 = [NSArray arrayWithObjects:@"A",@"B",@"C",@"D",@"E",nil];
    NSArray *secondArray05 = [NSArray arrayWithObjects:@"1",@"2",@"3",@"4",@"5",nil];
    NSDictionary *bigDic06 = [NSDictionary dictionaryWithObjectsAndKeys:firstArray05,@"first",secondArray05,@"second", nil];
    NSLog(@"%@",bigDic06);

    // 方式一
    for (int i =0; i < [bigDic06 count]; i ++) {
        NSString *key_i = [[bigDic06 allKeys] objectAtIndex:i];
        NSArray *array_i  = [bigDic06 objectForKey:key_i];
        for (int j =0; j < [array_i count]; j ++) {

            NSString *string_j = [array_i objectAtIndex:j];
            NSLog(@"%@",string_j );
        }
    }

    // 方式二
    NSArray *bigArray01 = [bigDic06 allValues];
    for (int i = 0; i <[bigArray01 count]; i ++) {
        NSArray *smallArray_i = [bigArray01 objectAtIndex:i];
        for (int j = 0; j < [smallArray_i count]; j ++) {

            NSString *value_j = [smallArray_i objectAtIndex:j];
            NSLog(@"%@",value_j);
        }
    }


    // 字典嵌套字典
    NSDictionary *stuDic1 = [NSDictionary dictionaryWithObjectsAndKeys:@"Rosie",@"name",@"female",@"sex",@"18",@"age", nil];
    NSDictionary *stuDic2 = [NSDictionary dictionaryWithObjectsAndKeys:@"Olivia",@"name",@"female",@"sex",@"19",@"age", nil];
    NSDictionary *bigDic09 = [NSDictionary dictionaryWithObjectsAndKeys:stuDic1,@"stu1",stuDic2,@"stu2", nil];
    // 方式一：采用 for...in...
    for (NSString *key in bigDic09) {
        NSDictionary *smallDic = [bigDic09 objectForKey:key];
        for (NSString *key in smallDic) {
            NSString *value = [smallDic objectForKey:key];
            NSLog(@"%@",value);
        }
    }

    // 方式二
    for (int i = 0; i < [bigDic09 count]; i ++) {

        NSDictionary *smallDic_i = [bigDic09 objectForKey:[[bigDic09 allKeys] objectAtIndex:i]];
        for (int j = 0; j < [smallDic_i count]; j++) {
            NSString *value = [smallDic_i objectForKey:[[smallDic_i allKeys] objectAtIndex:j]];
            NSLog(@"%@",value);
        }
    }

    // 方式三
    NSArray *values06 = [bigDic09 allValues];
    for (int i = 0; i < [values06 count]; i ++) {
        NSDictionary *dic_i = [values06 objectAtIndex:i];
        NSArray *array_i = [dic_i allValues];
        for (int j = 0; j < [array_i count]; j ++) {

            NSString *str_j = [array_i objectAtIndex:j];
            NSLog(@"%@",str_j);
        }
    }

NSMutableDictionary

1 - 代码示例

① 如何使用 NSMutableDictionary

    // 创建
    NSMutableDictionary *dic06 = [NSMutableDictionary dictionaryWithCapacity:1];
    // 可直接追加键值对儿
    [dic06 setObject:@"Cara"forKey:@"name"];
    [dic06 setObject:@"female"forKey:@"sex"];
    NSNumber *number = [NSNumber numberWithInt: 18];
    [dic06 setObject:number forKey:@"age"];
    NSLog(@"%@",dic06);

    // 删除
    [dic06 removeObjectForKey:@"name"];
    NSLog(@"%@",dic06);
    // 删除所有
    [dic06 removeAllObjects];
    NSLog(@"%@",dic06);

集合

1 - 集合特性：① 存储对象；② 无序存储；③ 随机获取数据；④ 元素不能重复

2 - 代码示例

① NSSet

    // 存在重复元素 one
    NSSet *set0 = [[NSSet alloc] initWithObjects:@"one",@"one",@"one",@"two",@"three",@"four", @"a", @"b", @"c", @"d",nil];
    NSLog(@"set0 = %@",set0); // 只会显示 1 个 one
    // set0 = {(one, c, two, d, three, four, a, b)}
    
    // 存在重复元素 b
    NSSet *set1 = [NSSet setWithObjects:@"a", @"b", @"b", @"d", @"e",set0,nil];
    NSLog(@"set1 = %@",set1);
    // set1 = {(d, b, {(one,c,two,d,three,four,a,b)}, e, a)}

    // 是否存在有相同元素的对象
    BOOL isIntersect = [set1 intersectsSet:set0]; // 1


    // 数组转化成集合
    NSArray *array = [NSArray arrayWithObjects:@"a", @"b", @"c",@"d", nil];
    NSSet *set3    = [NSSet setWithArray:array];
    
    // 集合个数：重复的对象计数为 1
    NSLog(@"set0 count：%lu", set0.count); // 8
    // 以数组的形式获取集合中的所有对象
    NSArray *allObj = [set0 allObjects];
    NSLog(@"set0-allObj：%@", allObj); // {(one, c, two, d, three, four, a, b)}

    // 是否包含某个对象
    NSLog(@"Is set3 coatains a ？ %d", [set3 containsObject:@"a"]);// 1
    // 是否相等
    NSLog(@"set1 isEqualto set3 ？ %d", [set1 isEqualToSet:set3]);// 0
    // 是否是子集合
    NSLog(@"set1 isSubSet of set3 ？ %d", [set1 isSubsetOfSet:set3]);// 0
    // 虽然 set1 中存在 set0， 但 set3 也不是 set1 的子集
    NSLog(@"set3 isSubSet of set1 ？ %d", [set3 isSubsetOfSet:set1]);// 0

    NSSet *set4 = [NSSet setWithObjects:@"aaa", @"bbb", nil];
    // 加
    NSSet *set5 = [set4 setByAddingObjectsFromArray:array];
    NSLog(@"看看是什么：%@",set5); // {(aaa, c, d, a, bbb, b)}
    NSSet *set6 = [set5 setByAddingObject:@"fuck"];
    NSLog(@"set6 is : %@",set6); // {(aaa, c, d, a, bbb, fuck, b)}

    NSSet *set20 = [NSSet setWithObject:@"i am ok"];
    NSSet *set7 = [set6 setByAddingObjectsFromSet:set20];
    NSLog(@"set7 is : %@",set7); // {(aaa, c, d, a, bbb, fuck,  "i am ok", b)}

    // 任取一个对象
    NSSet *s = [set7 anyObject];
    NSLog(@"%@",s);

② NSMutableSet | NSCountedSet

    NSMutableSet *mutableSet = [[NSMutableSet alloc] init];
    // 添加
    [mutableSet addObject:@"1"];
    [mutableSet addObject:@"11"];
    [mutableSet addObject:@"111"];
    
    NSMutableSet *mutableSet1 = [NSMutableSet setWithObjects:@"1", @"2", @"3",@"c", nil];
    
    // 初始化一个新分配的集合
    NSMutableSet *mutableSet2 = [[NSMutableSet alloc] initWithCapacity:4];
    [mutableSet2 addObject:@"1"];
    [mutableSet2 addObject:@"2"];
    [mutableSet2 addObject:@"3"];
    [mutableSet2 addObject:@"b"];
    
    NSMutableSet *mutableSet3 = [NSMutableSet setWithCapacity:3];
    [mutableSet3 addObject:@"1"];
    [mutableSet3 addObject:@"2"];
    [mutableSet3 addObject:@"3"];
    
    // 减
    [mutableSet1 minusSet:mutableSet2]; // 1/2/3/c - 1/2/3/b
    NSLog(@"minus :%@", mutableSet1);   // c
    [mutableSet3 minusSet:mutableSet2]; // 1/2/3 - 1/2/3/b
    NSLog(@"minus :%@", mutableSet3);   // 空
    
    // 交集
    [mutableSet2 intersectSet:mutableSet];  // 1/2/3/b     1/11/111
    NSLog(@"intersect：%@", mutableSet2);   // 1
    // 合并
    [mutableSet2 unionSet:mutableSet1]; // 1    c
    NSLog(@"union：%@", mutableSet2);   // {(1, c)}
    
    // 删除
    [mutableSet2 removeObject:@"1"];
    [mutableSet2 removeAllObjects];
    NSLog(@"removeAll：%@", mutableSet2);// 空
    
    NSLog(@"重新初始化前 mutableSet：%@", mutableSet);// 1, 11, 111
    mutableSet =  [NSMutableSet setWithObjects:@"a",@"b",@"r" ,nil];
    NSLog(@"重新初始化后 mutableSet：%@", mutableSet);// a, b, r
    [mutableSet setSet:mutableSet1];
    NSLog(@"%@", mutableSet);// c
    
    // NSCountedSet 是 NSSet 子类，能够记录集合中元素重复的次数，它是可变集合
    NSCountedSet *countedSet = [[NSCountedSet alloc] initWithObjects:@"1",@"2",@"3",@"2",@"1", @"1",nil];
    NSLog(@"countedSet is :%@，count is: %lu",countedSet,countedSet.count);// 1,2,3      3
    NSLog(@"%lu",[countedSet countForObject:@"1"]);// 3
    [countedSet removeObject:@"2"];// 移除了一个 2，还剩下一个 2
    NSLog(@"countedSet is :%@",countedSet);// 1,2,3
    [countedSet removeObject:@"2"];// 彻底删干净 2
    NSLog(@"countedSet is :%@",countedSet);// 1,3
    
    // 注意同 NSMutableSet 的区别
    NSMutableSet *mutableSet10 = [NSMutableSet setWithObjects:@"1", @"2",@"2",@"2",@"3",@"c", nil];
    [mutableSet10 removeObject:@"2"];// 把 @"2" 这个元素彻底移除，包含重复的
    NSLog(@"mutableSet10 is %@",mutableSet10);// 1,3,c