Programmer Group

Set WeakSet Map WeakMap WeakRef Set Set itself is a constructor used to generate set data structure. Similar to an array, the value is unique without repetition. const s = new Set(); s.add("a"); // add to s.add("b"); console.log(s, s.size); // Set { 'a', 'b' } 2 When adding a value to Set, no type conversion occurs, that is, 5 and "5&qu ...

catalogue   1, Concept 1. Program, process, thread 2, Creation and use of threads 1. By inheriting the Thread class 2. By implementing the Runnable interface: 3. Related methods in Thread class 4. Thread priority 3, Thread life cycle   1. Several states of threads 4, Thread synchronization   1. Synchronous code block ...

1. Picture loading, displaying and saving cv2.imread(filename, flags): read and load images cv2.imshow(winname, mat): displays a picture cv2.waitKey(): wait for the picture to close cv2.imwrite(filename, img): save the picture 2. Image display window creation and destruction cv2.namedWindow(winname, attribute): create a window cv2.destro ...

Code clipping algorithm for line segment For example, many uneven straight-line segments are distributed on a canvas, and we want to find a rectangular window on the canvas and only want to get the straight-line segments in the rectangular window. How should we achieve this? We know that the straight line segment can be expressed by a para ...

Documentation for mybatis3 version -- > mybatis document Write in front Ok, which is also the part of dynamic sql; It should be noted that later, I added a column recording age to the employee table. Of course, I also added attributes and its getset method to the Employee class; Construction method; toString(); These are also added with ...

Pass-1 js authentication bypass First, before we start, we need to create a new folder in the upload labs file we imported to facilitate us to upload php files   Open the first level and we can see this page   We will pass on the Trojan horse file with a good word in advance You can see the prompt that the folder format is incorre ...

1, Install Maven Installation path: click the link to download the required version directly Maven official website 1, Download method of the latest version 1. Click the link to enter Maven's official website 2. Find Download Files in the left column to Download 2, Download methods of all versions (including new and old versions ...

Interrupt knowledge point EXTI0 to EXTI15 are used for GPIO. Any GPIO can be used as the input source of EXTI through programming control. EXTI0 can be selected and configured as PA0, PB0, PC0, PD0, PE0, PF0, PG0, PH0 or PI0 through the EXTI0[3:0] bit of 1 (AFIO_EXTICR1) of AFIO's external interrupt configuration register. See figure. The ...

NoSQL database NoSQL generally refers to non relational databases, which can be a good supplement to relational databases. With the rise of Internet web2.0 websites, the traditional relational database has been unable to cope with web2.0 websites, especially the super large-scale and highly concurrent SNS type web2.0 pure dynamic websites, whic ...

Brain map: https://www.processon.com/mindmap/6179408f0e3e7416bdeb81d1 development environment Mac C locale configuration Software: Visual Studio Code Coder Runner plug-in 1, Overview of data structures 1. Definition How do we save a large number of complex problems in reality to the main memory (memory) with specific data type ...