Programmer Think

hashCode() and HashSet, compareTo() and TreeSet We often use Set in Java, but the author encountered a problem a few days ago. How to save the class he wrote into Set?? In the process of making force deduction, the generic parameters after Set are all wrapped classes, but some of the classes written by myself are not perfect enough, so the fu ...

Set frame diagram Note: the dotted line corresponds to the interface and the solid line corresponds to the implementation class Top level interfaces: Collection and Map Interface is to provide methods The Collection interface indicates that the stored data is a Collection composed of single data; The Map interface represents a collection of ...

Python ヾ (≥ ▽≤ *) o SET set type 1, Concept of set Set is one of the data types of Python, which is the same as the concept of set in mathematics Before explaining Python sets, I think it is necessary to review the main categories of mathematical sets: Union, intersection and difference Collections in Python If necessary, Pyth ...

brief introductionThe data structures of LinkedList and ArrayList are completely different. The bottom layer of ArrayList is the structure of array, while the bottom layer of LinkedList is the structure of linked list. It can carry out efficient insertion and removal operations. It is based on a two-way linked list structure.Overall structure d ...

After so much preparation, it finally started. Ha, ArrayList Kaigan! ArrayList should be the most frequently used collection class. Let's take a look at how the document introduces it. We can know that ArrayList is actually a replica of Vector, but it only removes thread safety. ArrayList is a List implementation that can be dynamically resize ...

prefaceArrayList is a List implemented by array. Compared with array, it has the ability of dynamic expansion, so it can also be called dynamic array.Any type of data can be stored in the ArrayList collection, and it is a sequential container. The order of stored data is consistent with the order we put it in, and it also allows us to put null ...

preface Some time ago, a new employee came to the company. He said that the new employee had been outsourcing code for one and a half years before he came to our company. Once I chatted with him about List. I casually asked him how to solve the unsafe multi-threaded concurrency of List collection when outsourcing. Unexpectedly, he looked at me ...

In this article, we begin to learn the Set data types and related operations in Python. Collection data type A collection in Python is an unordered list of immutable elements. This means: The elements in the collection have no order.The elements in the collection are unique. Duplicate elements are not allowed in the collection.Elements in a ...

You can use collection objects when you need to delete duplicates in a sequence or when you intend to perform some mathematical operations. A collection is an unordered container of hashable objects. You'll learn more about hashable objects later, and now remember that only immutable data types can be elements of a collection. Because of their ...

In the previous article, I have published common interview questions. Here I spent some time sorting out the corresponding answers. Due to my limited personal ability, it may not be in place. If there are unreasonable answers, please give me some advice. Thank you here. This article mainly describes the collection content that is almost necess ...