js review: prototype chain

Prototype chain The prototype chain is actually a mechanism of inheritance in JavaScript. Before we understand the prototype chain, we should first understand several concepts: this, ordinary object and function object, constructor, new. this This is a confusing concept for many people, but to understand the prototype chain we have to understan ...

Posted by billspeg on Wed, 08 May 2019 06:15:04 +0200

Technical summary

Install pygame module Install modules for making games Installation through pip command pip install pygame Game Initialization and Exit Initialization pygame.init() Sign out pygame.quit() Rectangular area object Four Elements of Rectangular Area x coordinates, y coordinates, width, height x,y,width,heigh Descri ...

Posted by khefner on Wed, 08 May 2019 02:15:03 +0200

Array Knowledge Point Arrangement

Array Knowledge Point Arrangement [the most detailed and comprehensive] array Why learn arrays? The Concept of array Initialization of arrays Array Notes Traversal of arrays On Value Passing and Reference Passing in Arrays array Hello! This chapter mainly collates the knowledge points related to arrays. If you want to ...

Posted by suave4u on Tue, 07 May 2019 13:30:03 +0200

NEO400J Level Full-Text Index Construction Optimization

NEO400J Level Full-Text Index Construction Optimization 1. Scale of data volume (level 100 million) 2. Ways to Build Indexes 3. Exceptions Occurring in Index Building IV. Code optimization for full-text index 1,Java.lang.OutOfMemoryError 2. When accessing a database 3. Optimizing scheme 4. Optimize Code 5. Perform efficiency ...

Posted by lisa007 on Tue, 07 May 2019 12:10:06 +0200

Python 3 object-oriented programming, error and exception handling

Class and instance Classes are abstract templates, and instances are concrete "objects" created according to classes. Terminology explanation Class: A collection of objects that describe the same properties and methods. It defines the properties and methods common to each object in the set. Objects are instances of ...

Posted by kevgais on Tue, 07 May 2019 10:40:04 +0200

mybatis input mapping and output mapping

1. parameterType (input type) (1) Pass simple types (such as int, which we can use directly) public Student getStudentById(Integer studentId); <select id="getStudentById" parameterType="int" resultType="student"> select * from tblstudent where studentId = #{studentId} </select> (2) Passing pojo objects     p ...

Posted by bogins on Mon, 06 May 2019 22:55:03 +0200

scale Gradient Scaling for Android Basic Animation

Xiaocai recently learned about ViewPager's animation, which I am ashamed to say has not been carefully understood for so long. Today, I intentionally learn about Android's basic animation. Android's basic animations include alpha (transparency) / scale (zooming) / translate (displacement) / rotate (rotation). Learn about scale gradient zooming ...

Posted by s1m0n on Mon, 06 May 2019 08:45:04 +0200

Lesson 086: Pygame: Collision Detection | Learning Records

Today we are going to learn collision detection. Most games need to do collision detection because you need to know whether the ball collided, whether the bullet hit the target, whether the protagonist stepped on the shit. How should that be achieved? To put it bluntly, the principle is simple, that is, to detect whether there i ...

Posted by TreeNode on Sun, 05 May 2019 15:48:04 +0200