• Rust programming video tutorial (Advanced) – 011_ 3 dereference polymorphism


    Video address Headline address:https://www.ixigua.com/i677586170644791348…Station B address:https://www.bilibili.com/video/av81202308/ Source address GitHub address:https://github.com/anonymousGiga/learn_rus… Explanation content 1. Dereference forced polymorphismExample: follow the example above fn hello(name: &str) { println!(“Hello, {}!”, name); } fn main() { let m = MyBox::new(String::from(“Rust”)); hello(&m); // When dereferencing here, force polymorphism and change & string to & str. otherwise, you need: Hello (& (* […]

  • Java object oriented instanceof keyword


    entrance   Java has three object-oriented features: Encapsulation: Some information of the class is hidden inside the class, and external programs are not allowed to access it directly. Instead, the operation and access of hidden information are realized through the methods provided by the class. Inheritance: Inheritance is a kind of relationship between classes, which […]

  • Talk about dependency injection annotations @ resource and @ Autowired


    1. Preface @[email protected] can be found inSpring FrameworkDeclarative dependency injection in applications. And the interview often involves the knowledge points of these two annotations. Today, let’s summarize them. 2. @Resource Full namejavax.annotation.Resource, it belongs toJSR-250An annotation of the specification, includingJakarta EE(J2EE)Yes.SpringProvides support for this annotation. Let’s learn more about the rules of this annotation. This […]

  • Simply understand the principles of Java polymorphic upward transformation


    This article mainly introduces the principles related to the simple understanding of Java polymorphic upward transformation. It is introduced in great detail through the example code, which has a certain reference value for everyone’s study or work. Friends in need can refer to it Polymorphism is the third feature of object-oriented. Advantages of polymorphism Improve […]

  • Implementation of polymorphism and multiple inheritance in C + + and Java


    Polymorphism problem During the school recruitment interview, the author was asked the famous question “how to realize polymorphism in C + + and Java”, and then unfortunately overturned. It’s too famous to prepare. It’s only related to the virtual function table. After the interview, the similarities and differences between the implementation of C + + […]

  • Eloquent orm of laravel


    1、 ORM programming idea 1.1 active record design mode     Active RecordIt’s a kind ofData access design pattern, it can help you implement data objectsObjectMapping to a relational database. applicationActive RecordThe instance object of each class uniquely corresponds to a row (one-to-one relationship) of a database table. You only need to inherit oneabstract Active RecordClass can […]

  • An article takes you to understand the “Object-Oriented” in JavaScript


    Author | jeskson Source: dada front end Tavern Install webpack, packaging tool, webpack dev server, Babel, parse ES6 syntax, and initialize NPM environment. npm install webpack webpack-cli –save-dev webpack.dev.config.js module.exports = { entry: ‘./src/index.js’, output: { path: __dirname, filename: ‘./release/bundle.js’ } } index.js class Person { constructor(name) { this.name = name } getName() { return […]

  • [go] type assertion and type judgment are in the form of if and type switch


    Use type assertions to determine whether an interface is a specified type If this simplified form:if _,ok:=x.(T);ok{ } Type switch type judgment form switch t := x.(type) { case int: fmt.Printf(1) case nil: fmt.Printf(2) default: fmt.Printf(3) }    Type assertion makes variables of the same interface behave differently at different times, which is the essence […]

  • Rust programming video tutorial (Advanced) — 028_ 2 return closure


    Video address Headline address:https://www.ixigua.com/i677586170644791348…Station B address:https://www.bilibili.com/video/av81202308/ Source address GitHub address:https://github.com/anonymousGiga/learn_rus… Explanation content Return closureError example: fn returns_closure() -> Fn(i32) -> i32 { |x| x + 1 } Correct example: fn returns_closure() -> Box<dyn Fn(i32) -> i32> { Box::new(|x| x + 1) } fn main() { let c = returns_closure(); println!(“r = {}”, c(1)); //Equivalent to […]

  • Analysis of dynamic binding principle in Java polymorphism


    This article mainly introduces the dynamic binding principle of Java polymorphism analysis, the article through the example code is very detailed, for everyone’s study or work has a certain reference learning value, need friends can refer to Polymorphism is a very important feature of object-oriented programming, which makes the program more readable and extensible. It […]

  • C + + object model analysis (2)


    C + + object model analysis (2) Inherited object model Within the C + + compiler, classes can be understood as structs Subclass is obtained by adding new members of subclass to member function of parent class class Derived : public Demo { int mk; }; Programming experiment 1: a preliminary study of inheritance object […]

  • C + + object oriented: C + + polymorphism


        ​ Polymorphism literally means multiple forms. Polymorphism is used when there is a hierarchy between classes and classes are associated by inheritance. C + + polymorphism means that when a member function is called, different functions will be executed according to the type of the object calling the function. Xiaobian recommends a Clanguage/C++My […]