Comments can be used to explain Java code, and to make it more readable. It can also be used to prevent execution when testing 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 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"); It's up to you which one you use. Normally, we use // for short comments, and /* */ for longer.