With the FDT plugin, Eclipse turns your JavaDoc comments into popups that appear whenever hovering over a code that has JavaDoc comments attached to it. This can be any class, member variable or function. Attaching comments is done by putting a comment right over the element you wish to attach it to, in JavaDoc style:
/**my comment for myElement*/
myElement


For a long time, it has been a habit to use long separation lines consisting of dashes for functions. Though this may increase separation of functions in a class file a little, those long lines also appear in the popup that Eclipse creates. It is therefore strongly recommended to let go of the little dashes, and use “clean” comments, like this:
/**
*    The function description
*    @param ...: a parameter description
*    @return : description of the return value
*/


For public variables, a single line JavaDoc comment can be added on the line over the declaration:
/** objects of type MyData */
public var myList:Array;