Detailed explanation of Set object and Map object in front-end JS (probability, creation, use method, etc.)

Map and Set Map and Set are two new data types in ES6Are built-in constructorsInstantiate using new Set It is used in conjunction with new const s = new Set() console.log(s) /* Set(0) {} [[Entries]] No properties size: (...) __proto__: Set */ Is a data set We can add data directly to the inside when ...

Posted on Mon, 20 Sep 2021 03:40:42 -0400 by mulysa

Collection collection (super detailed)

Collection 1, Collection overview 1. What is a collection? An array is a collection. A collection is a container used to hold data of other data types. The collection will put in the new objects and take them out one by one when in use. It is a carrier. 2. What does the collection store? Collections cannot directly store basic data typ ...

Posted on Sun, 19 Sep 2021 02:01:05 -0400 by ajcalvert

Java collection -- Set interface and its implementation classes HashSet, LinkedHashSet and TreeSet

Set Interface Overview 1. The set interface is a sub interface of the Collection. The set interface does not define additional methods, but uses the methods in the Collection interface. 2. The Set set cannot contain the same elements. If you try to add two identical elements to the same Set set, the add operation fails. 3. Set: store ...

Posted on Thu, 16 Sep 2021 21:05:26 -0400 by spfoonnewb

Java learning notes: high level syntax

1, Introduction to multithreading: ① Processes and threads: What is a process? A process is a task running in the operating system (an application running in a process).A process is an area of memory that contains certain resources. The operating system uses processes to divide its work into functional units.One or more execution unit ...

Posted on Wed, 08 Sep 2021 13:36:36 -0400 by Nakor

Collection framework of java

introduce Collection interface and its derivatives What is the collection? Simply put, it is a encapsulated data structure Looking at a picture, we need to clarify the relationship inside: Classification of each color: (divided into three types) The relationship between the three should be clearly sorted out according to the directio ...

Posted on Sun, 05 Sep 2021 21:30:11 -0400 by Thundarfoot

The Principle of HashSet, TreeSet, LinkedHashSet and the Use of Thread Security

1. Principles           1,HashSet         The underlying hashset layer actually maintains a HashMap instance.The underlying data structure is a hash table.Combines the advantages of arrays and chained lists.It has the following characteristics:         (1) Collections of duplicate values are not allow ...

Posted on Sat, 04 Sep 2021 19:07:42 -0400 by p2grace