Java annotations, keywords, and identifiers

Comments:

Single-line comment//comment content

Multiline comment/* Comment content */

Document Comments/** Comments */

"Comments are used to make it easier for writers and others to read the source code and to enhance their understanding of the code.

Where a document comment is basically the same as a multiline comment, the only difference is that the document comment can use the Javadoc.exe command to generate the API document "

Key words

Keywords are special meanings given by the Java language, words with specialized purpose, and keywords in Java are lowercase.

1    Abstract 　　 assert 　　 Boolean 　　     Break 　　    byte2  　　  Case 　　　    Catch 　　  Char 　　　    class 　　    Const3  　　 Continue 　    default 　     Do 　　　　  Double 　     Else4  　　 enum 　　     extends 　  Final 　　　   finally 　　   float5  　　  for 　　　　   Goto 　　    if 　　　  Implements 　    Import6  　　 instanceof 　  int 　　　   Interface 　    Long 　　     native7  　　 New 　　　　  Package   Private 　   protected  　     Public8  　　 return 　　　 STRICTFP 　　  Short 　　     Staticuper9  　　 Switch 　  synchronized    This 　　      Throw 　      throwsTen  　　 transient 　　 Try 　　　   void 　　　   volatile

Identifier

Identifiers are the meanings of names, and all names are collectively referred to as identifiers. In Java, you often define classes, methods, and variables, and always give them names when defining them, which are identifiers.

1. Constituent elements

English characters: a-z,a-z "all Letters"

Number: 0-9 "all Numbers"

Symbols: _ With $

2. Rules for identifiers

Cannot start with a number

You cannot use keywords

Strictly case-sensitive, do not limit the length of the naming, as far as possible to achieve the name of understanding

　　

　　

Java annotations, keywords, and identifiers