Single-line comments and multi-line comments in Java

In programming, comments are an essential part. On the one hand, comments can clearly see the structure of the code and make it easier to find. On the other hand, they are also conducive to work handover between colleagues. So today I will talk to you about single-line comments and multi-line comments in Java. Friends in need can refer to it. I hope it will be helpful to you.

What are comments? A comment is a piece of text. This text is not necessary and does not directly participate in the running of the code.

Comments are used to explain the function of a certain piece of code, or the purpose of a certain class, the function of each method, and the data types and meanings of the method's parameters and return values, etc.

Why add comments?

1. Never trust your own understanding too much. In order to understand your previous code simply and clearly over time, it is recommended to add comments.
2, readability first, efficiency second. In team collaborative development, communication among team members is more important. In order for the code you write to be understood by the entire team, it is recommended to add comments.
3, code is documentation. I usually write some code. In order to generate some standardized documents, it is recommended to add comments.

In actual work, I often hear some colleagues say that other people’s code has no comments. In fact, beautifully written code does not require too many comments. On the contrary, I personally don’t like comments that fill the screen. Or some useless code is extremely disgusting. Especially after using git, svn and other tools for version management, I will delete all the useless commented out code.

Here is my personal understanding of annotations:

1. Necessary annotations must be present. For example, the meaning of fields in Javabeans should have relevant annotations. For example, some functions are temporarily implemented in some coding, but there are some bad areas that need to be optimized. I usually write a TODO to implement the basic functions and then go back and improve them myself.
2. Don’t write some idiotic useless comments, and don’t keep any commented out lines of code. Nowadays, codes are generally managed by version tools, so there is no need to worry about the code being lost.
3. Strictly abide by Java's naming conventions. Don't worry about variable names being too long, and don't worry about method names being too long. Reasonable English translation naming is much better than writing useless Chinese comments.

Program comments are an important part of the source code. For a standardized program source code, comments should account for about one-third of the source code.

Almost all programming languages ​​provide the comment function. General programming languages ​​provide basic single-line comments and multi-line comments, and Java is no exception. In addition, the Java language also provides a documentation comment.

This blog will first sort out single-line comments and multi-line comments in Java. Documentation comments are generally used to generate APIs.

Single-line comments and multi-line comments

A single-line comment is to comment a line of code in the program. In Java language, put the double slash "//" where necessary Just put the content of the annotation before.

In eclipse, the shortcut key for single-line comments is command /. Press it once to add a comment, and press it again to cancel the comment.

Multi-line comments are to comment out multiple lines of code in the program at once. In the Java language, use "/*" and "*/" to include the content that needs to be commented in the program, "/ *" indicates the beginning of a comment, and "*/" indicates the end of a comment.

In eclipse, the shortcut key for multi-line comments is command control /. You need to select the code when using it. I rarely use multi-line comments.

Now post a piece of code to demonstrate single-line comments and multi-line comments in Java.

/**
 * Java的单行注释和多行注释.
 * 
 * @author LinkinPark
 */
public class Comment
{
 public static void main(String[] args)
 {
  // 这里是Java的单行注释
  System.out.println("演示Java的单行注释。。。");
  /*
   * 这里是Java的多行注释
   */
  System.out.println("演示Java的多行注释。。。");
 }
}

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