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preface Unlike Java and other languages, JavaScript does not have any printing or output methods. It usually uses the following four ways to output data. Use window Alert() is used to pop up a warning boxUse document Write() writes the content to the HTML documentUse innerHTML to write to HTML elementsUse console Log() is written to the brows ...

regular expression 1. Learning objectives Master the function of regular expressionsMaster the syntax of regular expressionsLearn about common regular expressions 2. Content explanation 2.1 concept of regular expression Regular expression is a logical formula for string operation. It uses some specific characters defined in advance and th ...

ServletConfig object Effect This object allows you to read the web. Initialization parameters configured in xml. Why put parameter information on the web? XML file? A: Make your program more flexible [change the profile web.xml without changing the program code] Get the web. Parameter information for XML file configuration web.xml configur ...

Java Web - Database Connection Pool and DBUtils Tools Database Connection Pool Definition In JDBC programming, each time a Connection object is created and disconnected, it takes time and IO resources. This is because when a Java program establishes a connection to a database, the database side verifies the user name and password, and to ...

         In the development process of Java Web, Servlet was first responsible for the development of display layer (page). Later, because JSP has more advantages in the development of page layer, it comprehensively replaced Servlet and acted as the development of page layer.     &nbsp ...

What is JSON? ssdssJSON (JavaScript Object Notation) is a lightweight data exchange format. Easy to read and write. It is also easy to machine parse and generate. JSON adopts a text format completely independent of language, and many languages provide support for JSON (including C, C++, C#, Java, JavaScript, Perl, Python, etc.). This makes JS ...

1. Parameter transfer 1.1 class name as formal parameter and return value (application) 1. The class name is used as the formal parameter of the method The formal parameter of the method is the class name. In fact, what is needed is the object of the class The address value of the object is actually passed 2. The class name is used as the r ...

1.ArrayList 1.1ArrayList class overview [understanding] What is a collection A storage model with variable storage space is provided, and the stored data capacity can be changed Characteristics of ArrayList set The bottom layer is implemented by array, and the length can be changed Use of generics The data type used to constrain the storag ...

Asdsscss is a set of extended style standards formulated by W3C association to make up for the deficiency of HTML in display attribute setting. Its full name is Cascading Style Sheet. CSS standard redefines the original text display style in HTML and adds some new concepts, such as class and layer, which can overlap and locate text. Before CSS ...