ActionScript 3.0 code supports two types of comments: single line comments and multi-line comments. These commenting mechanisms are similar to the commenting mechanisms available in C++ and Java. The compiler will ignore text that is marked as a comment.Single line comments begin with two forward slash characters (//) and continue until the end of the line. For example, the following code contains a single line comment.
var someNumber:Number = 3; // This is a single line comment
Multi-line comments begin with a forward slash and asterisk (/*) and end with an asterisk and forward slash (*/).
/* This is multi-line comment that can spanmore than one line of code */