Basic syntax for Java

Java language is strictly case sensitive

Multiple classes can be defined in a Java source file, but only one of the classes is defined as the public class

If the source file contains the public class, the name of the source file must be the same as the public class

public class Test{public static void Main (string[] args) {System.out.println ("Hello world!");}}

Compile

If the name is inconsistent, the error will be

When a source file contains multiple classes, a successful compilation generates a corresponding number of bytecode files, that is, each class generates a separate class file, and the byte-code file name is the same as its corresponding class name

public class Test{public static void Main (string[] args) {System.out.println ("Hello world!");}} Class A{}class B{}class c{}

Compile

If a class must run, you must have the main method, because the main method is the primary entry of the program

Programming Recommendations:

A Java source file defines only one class, and different classes use different source file definitions

Defines the individually defined classes in each source file as public

Keep the Java source file name consistent with the class name in the source file

Basic syntax for Java