int main(int argc, const char * argv[])
{
    @autoreleasepool {
        /*不可变数组*/
        //创建不可变数组 方式一
        NSArray *arr=[NSArray arrayWithObjects:@"周一",@"周二",@"周三",@"周四",@"周五",@"周六",@"周日",nil];
        for(int i=0;i<[arr count];i++){
            NSLog(@"%@",[arr objectAtIndex:i]);
        }
        //创建不可变数组 方式二
        NSArray *arr1=@[@"周一",@"周二",@"周三",@"周四",@"周五",@"周六",@"周日"];
        for(int i=0;i<[arr1 count];i++){
            NSLog(@"%@",arr1[i]);
        }
    }
}

int main(int argc, const char * argv[])
{
    @autoreleasepool {
        /*可变数组*/
        NSMutableArray *marr=[NSMutableArray array];
        for (int i=0; i<3; i++) {
            marr[i]=@(i+1);
        }
        [marr addObject:@(4)];
        for (int i=0; i<[marr count]; i++) {
            NSLog(@"%@",marr[i]);
        }
        NSLog(@"%@",marr);
     }
}

int main(int argc, const char * argv[])
{
    @autoreleasepool {
        /*不可变词典*/
        NSDictionary *dic=[NSDictionary dictionaryWithObjectsAndKeys:@"学生",@"1",@"教师",@"2", nil];
        for (NSString *key in dic) {
            NSLog(@"key:%@ value:%@",key,[dic objectForKey:key]);
        }
     }
}

int main(int argc, const char * argv[])
{
    @autoreleasepool {
        /*可变词典*/
        //创建可变词典对象
        NSMutableDictionary *mdic=[NSMutableDictionary dictionary];
        //添加键值对
        [mdic setObject:@"学生" forKey:@"1"];
        mdic[@"2"]=@"教师";
        //显示键值对
        NSLog(@"key:1 value is:%@",[mdic objectForKey:@"1"]);//key:1 value is:学生
        NSLog(@"key:2 value is:%@",mdic[@"2"]);//key:2 value is:教师
        //删除
        [mdic removeObjectForKey:@"1"];
        NSLog(@"mdic count:%lu",[mdic count]);//mdic count:1
        [mdic removeAllObjects];
        NSLog(@"mdic count:%lu",[mdic count]);//mdic count:0
     }
}