Programmer Think

1. General Caterpillar effect: In one experiment, many caterpillars were placed on the edge of a flowerpot to make them connect head to tail and form a circle. Then sprinkled some caterpillar food near the flowerpot. At this time, caterpillars do not climb in the direction of food, but circle one by one at the edge of the flowerpot until they d ...

Promise meaning Promise is a solution for asynchronous programming, which is more reasonable and powerful than traditional solutions - callback functions and events. It was first proposed and implemented by the community. ES6 has written it into the language standard, unified the usage, and provided promise objects natively. Promise is simply ...

The plug-in library often needs to be developed globally, or exception handling is required:Handle exceptions globally;Prompt error messages for developers;Scheme degradation processing, etc.So how to realize the above functions?This paper first briefly implements an exception handling method, then introduces it in detail combined with the impl ...

prefaceAntV It is a new generation of data visualization solution of ant financial services. X6 is mainly used to solve the solutions related to the field of graph editing. It is a graph editing engine with built-in functions and components required by the editor. This paper aims to have a general understanding of some underlying engines in the ...

re module 1,re.match function re.match attempts to match from the starting position of a string. If it cannot match from the starting position, it returns None. Syntax: re match(pattern, string, flags=0) Parameters: pattern -- regular expression String -- matching string flags -- flag bit, which is used to control the matching method of ...

In a quick review, flex layout is basically used I Basic concepts of Flex layout All child elements of the Flex layout automatically become members of the container, called Flex items. The container has two axes: the main axis and the cross axis. As shown in the figure below. II The attribute of the container (that is, the attribute of the ...

[JavaScript] Web magnifying glass effect case Deepen the understanding and application of e.pageX, e.pageY, offsetLeft, offsetTop, offsetWidth and offsetHeightApplication of mouse events mouseover, mouseout and MouseMove Implementation effect: the mouse moves in the small picture on the left, and the enlarged effect of this part of the area i ...

What is responsive? catalogue Function encapsulation Class encapsulation Listening object change let m = 3 console.log(m); console.log(m +'1aaaaaa'); console.log('hello'); When the value of m changes, I hope the following three lines of code will be executed again automatically. // obj const obj = { name:'Sherry', age:18 } cons ...

route Understanding: a route is a set of key - value s. Multiple routes need to be managed by a router.Front end Routing: key is the path and value is the component. 1.router-link In vue, instead of using the regular a tag, we use a custom component router link to create links. This allows Vue Router to change the URL and handle URL generatio ...

0 @WebServlet annotation usage 0.1 configuration xml document header Note: if the annotation is "0-version", please note that the configuration is "version-3" <?xml version="1.0" encoding="UTF-8"?> <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instanc ...