OC - 集合

数组

                // 实例方法初始化
        NSArray *array = [[NSArray alloc] initWithObjects:@"1",@"2",@"3",nil];
        NSArray *array1 = [[NSArray alloc] initWithArray:array];
        NSLog(@"array = %@,array1 = %@",array,array1);

                //便利初始化方法
        NSArray *array2 = [NSArray arrayWithObjects:@"3",@"4", nil];

                //简化操作
        NSInteger age = 10;

        NSArray *array3 = @[@"5",@"6",@(age)];
        NSLog(@"array3 = %@",array3);

                //获取数组元素个数
        NSUInteger count =  array3.count;
        [array3 count];

数组的运算:

                // 实例方法初始化
        NSArray *array = [[NSArray alloc] initWithObjects:@"1",@"2",@"3",nil];
        NSArray *array1 = [[NSArray alloc] initWithArray:array];
        NSLog(@"array = %@,array1 = %@",array,array1);

                //便利初始化方法
        NSArray *array2 = [NSArray arrayWithObjects:@"3",@"4", nil];

                //简化操作
        NSInteger age = 10;
        NSArray *array3 = @[@"5",@"6",@(age)];
        NSLog(@"array3 = %@",array3);

                //获取数组元素个数
        NSUInteger count =  array3.count;

        [array3 count];

数组的排序

        NSArray *array = @[@"12",@"3",@"6",@"2",@"1"];

        NSArray *sortArray = [array sortedArrayUsingSelector:@selector(compare:)];
        NSLog(@"sort = %@",sortArray);

//        caseInsensitiveCompare,compare


      NSArray *sortArray1 = [array sortedArrayUsingComparator:^NSComparisonResult(id  _Nonnull obj1, id  _Nonnull obj2) {
            NSInteger a = [obj1 integerValue];
            NSInteger b = [obj2 integerValue];

            if (a > b) {
                return -1;
            }else if(a == b){
                return 0;
            }else{
                return 1;
            }

        }];

           NSLog(@"sort1 = %@",sortArray1);

数组的遍历

        NSArray *array = @[@"12",@"abcde",@6,@"2",@"1"];
        //普通遍历
        for (int i = 0; i < array.count ; i ++) {
            NSLog(@"%@",array[i]);
            NSLog(@"%@",[array objectAtIndex:i]);
        }

        //快速枚举

        for (id object in array) {
            NSLog(@"object = %@",object);

            }

NSMutableArray

        NSMutableArray *mutableArray = [NSMutableArray arrayWithObjects:@"1",@"2", nil];

        //增
        [mutableArray addObject:@"3"];
        NSLog(@"mutableArray = %@",mutableArray);

        //删
        [mutableArray removeObjectAtIndex:0];
        NSLog(@"mutableArray = %@",mutableArray);


        //查
        NSInteger index = [mutableArray indexOfObject:@"2"];

        NSLog(@"index = %ld",index);
        //改（替换）

        [mutableArray replaceObjectAtIndex:0 withObject:@"000"];
        NSLog(@"mutableArray = %@",mutableArray);

        //排序

        [mutableArray sortedArrayUsingSelector:@selector(compare:)];
        NSLog(@"mutableArray = %@",mutableArray);

iOS9 新特性

       NSArray<NSString *> *array = @[@"hello",@"world"];

        NSMutableArray<NSString *> *mutableArray = [NSMutableArray arrayWithObjects:@"uu", nil];
        [mutableArray addObject:@"3"];

字典NSDictionary

        //初始化

        NSDictionary *dictionary = [NSDictionary dictionaryWithObjectsAndKeys:@"one",@"1",@"two",@"2", nil];
        NSLog(@"dictionary = %@",dictionary);

        //字典的快速生成
        NSDictionary *newDictionary = @{
                                        @"1" : @"one",
                                        @"2" : @"two"
                                        };

        NSLog(@"dictionary = %@",newDictionary);

        //键值对的个数

        NSLog(@"%ld",dictionary.count);

        //查询一个对象
        NSString *string = dictionary[@"1"];
        NSLog(@"%@",string);

        NSString *string1 = [dictionary objectForKey:@"1"];
        NSLog(@"%@",string1);

        //取出所有的key
        NSArray *keys = [dictionary allKeys];

        //取出所有的对象
       NSArray *values = [dictionary allValues];
#pragma mark - 字典的遍历
        //因为字典是以key-value形式存在，所以不可以直接遍历出一对，只能keys 或 value
        //字典是无序的

        //根据key,遍历所有的value
        for (int i = 0; i < dictionary.count; i ++) {
            NSString *key = [keys objectAtIndex:i];
           // NSString *key = keys[i];

            NSString *value = [dictionary objectForKey:key];

           // NSString *value = dictionary[key];

            NSLog(@"value = %@",value);
        }

        //快速枚举:遍历字典，保存的是key
        for (id object in dictionary) {
            NSLog(@"object = %@",dictionary[object]);
        }

NSMutableDictionary

        //增:添加没有顺序

        NSMutableDictionary *mutableDictionary = [NSMutableDictionary dictionaryWithObjectsAndKeys:@"one",@"1",@"two",@"2", nil];

        [mutableDictionary setValue:@"three" forKey:@"3"];
        NSLog(@"mutable = %@",mutableDictionary);

        //删
        [mutableDictionary removeObjectForKey:@"3"];
        NSLog(@"mutable = %@",mutableDictionary);

        //查
        NSLog(@"%@",[mutableDictionary objectForKey:@"1"]);

        //改(根据key将原来的覆盖掉)
        //setobject...forkey方法，如果字典中没有添加的这个Key,就做添加处理，如果有，当修改处理

        [mutableDictionary setValue:@"three" forKey:@"1"];
        NSLog(@"mutable = %@",mutableDictionary);

        [mutableDictionary setObject:@"four" forKey:@"2"];
        NSLog(@"mutable = %@",mutableDictionary);

        //字典数组
        NSDictionary *dictionary1 = @{   @"A": @"YES",

                                        @"B":
                                        @{@"math" : @"tom",
                                       @"book" : @[@"english",@"chinese"]

                                       }

                                     };

        NSLog(@"%@", dictionary1[@"B"][@"book"][0]);

NSSet

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

        //取出一个
         NSLog(@"set1 = %@", [set anyObject]);

        //取所有的对象
          NSLog(@"set2 = %@",  [set allObjects]);
        //里面的对象不能存放重复对象，主要用于去除重复数