Comments in general : Comments « Language « Java Tutorial

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It is good practice to write comments explaining your code.

There are two types of comments in Java, both with syntax similar to comments in C and C++.

1. Traditional comments: Enclose a traditional comment in /* and */.
2. End-of-line comments: Use double slashes (//) which causes the rest of the line ignored by the compiler.

Traditional comments do not nest, which means

/*
  /* comment 1 */
  comment 2 */

1. is invalid because the first */ after the first /* will terminate
2. which will generate a compiler error

End-of-line comments can contain anything, including the sequences of characters /* and */, such as this:

// /* this comment is okay */