Java Comments

Comments can be used to explain Java code, and to make it more readable. It can also be used to prevent execution when testing an alternative code.

Single-line comments start with two forward slashes (//).

Any text between // and the end of the line is ignored by Java (will not be executed).

This example uses a single-line comment before a line of code:

// This is a comment
System.out.println("Hello World");


This example uses a single-line comment at the end of a line of code:

System.out.println("Hello World"); // This is a comment


Java Multi-line Comments

Multi-line comments start with /* and ends with */.

Any text between /* and */ will be ignored by Java.

This example uses a multi-line comment (a comment block) to explain the code:

/* The code below will print the words Hello World
to the screen, and it is amazing */
System.out.println("Hello World");


Java Documentation Comment

The documentation comment is used to create documentation API. To create documentation API, you need to use the javadoc tool.


/** The Calculator class provides methods to get addition and subtraction of given 2 numbers.*/  
public class Calculator {  
/** The add() method returns addition of given numbers.*/  
public static int add(int a, int b){return a+b;}  
/** The sub() method returns subtraction of given numbers.*/  
public static int sub(int a, int b){return a-b;}