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System structure of linux 1.linux is an inverted tree structure 2. Everything in Linux is a file These files are in the system top-level directory "/"/ is the root directory / directory below the secondary directory, these directories are automatically established when the system is installed. The role of secondary directorie ...

1. Introduction Principle: User-defined jsp tags.When a jsp page with a custom tag is compiled into a servlet by the jsp engine, the tag tag is converted into an operation on an object of a tag processor class. Tag Library API: Defined in javax.servlet.jsp.tagext   2. Lifecycle of label processor class implementing SimpleTag interface 1) setJs ...

Beautiful Soup is simple to parse HTML. API is very human. It supports CSS selector, HTML parser in Python standard library, and XML parser in lxml. Compared with regularity, it is simpler to use. Examples: First you have to import the bs4 Library #!/usr/bin/python3 # -*- conding:utf-8 -*- __author__ = 'mayi' from bs4 import BeautifulSoup h ...

1. Overview This chapter will analyze and explain Jquery attributes in conjunction with JQuery's official API. It mainly talks about. addClass (),. attr (),. hasClass (),. HTML (),. prop (),. removeAtrr (),. removeClass (),. removeProp (),. toggleClass (),. val (). 2. DOM attributes 2.1  .addClass() Adds a style to the specified ele ...

1. Vertical alignment If you use CSS, you will be confused: how do I align elements in the container vertically? Now, using CSS3 Transform, you can gracefully solve this puzzle: .verticalcenter{ position: relative; top: 50%; -webkit-transform: translateY(-50%); -o-transform: translateY(-50%); transform: translateY(-50%) ...

The blogger said: For any based on _____________ JavaScript For developers, this is absolutely a must-read article and a magic weapon to improve development efficiency. text 1. Ternary Operator When you want to write if...else statements in one line of code, it is a good choice to use ternary operators, such as: const x = 20 ...

Previous remarks ES5 contains five primitive types: Character string,number,Boolean value,null and undefined . ES6 introduces the sixth primitive type, Symbol The object attribute names of ES5 are strings, which can easily cause property name conflicts. For example, if you use an object provided by someone else and want to add a new method t ...

1. Quotations Today, there are quite a variety of programming languages, some of which have not even been heard or touched. For a programmer, C language is the foundation, C language is a process-oriented programming language, so how to use C language to write object-oriented programs? The three basic characteristics of object-oriented progr ...

1. let const block-level scope Deconstructive Assignment of Variables 1. Deconstructive Assignment of Variables let [a, b, c] = [1, 2, 3]; Extract values from arrays and assign values to variables according to their corresponding locations let [foo] = []; let [bar, foo] = [1]; If the deconstruction is unsuccessful, the value of the vari ...

This year's graduation project is about big data and machine learning. Because that time has entered the front-end industry naturally choose to use JavaScript to implement the specific algorithm. Although JavaScript is not the best language for big data processing and has no advantage over other languages, it improves our understanding of js an ...