Having issues trying to pass an object class to be sorted via Heap Sort. Basically I have a class which holds employee data such as names, address, phone numbers and employee ID. We are to use Heap Sort to pass this class as a object and sort it by employee ID. My main issue is converting my heap sort structures to where they can take objects. This is for a beginning data structures course so we're not allowed to use advanced techniques. My road block is I'm stumped as to how to pass my objects into the heap sort methods which currently only take primitive data types. Example instead of: buildHeap(int  currArray) it needs to take it as a object like buildHeap(OfficeStaff  currArray). Its when I get down into the code below I start getting "cant convert from "int to object etc..." errors.
I don't know the algorithm for heap sort, but I know all types of sort take object1 and object2 and compare them to see whether they are “larger” or “smaller”. So you can sort an int because it is obvious that ints are “larger” or “smaller” than each other. So you have to make your Employee objects “larger” or “smaller” than each other. And there are several ways to do that. I suggest you start with the Java® Tutorials because that section on “ordering” is very helpful. You can create Comparators which will tell you whether your Employees earn more or less, or have been working for you the longest, or to sort them in order of name. But you will find more about that in the link I gave you.
Also please check the formatting of your code. Your indentation is inconsistent, and you have too few blank lines in the first class (each method should be preceded by an empty line, for example.) You had too many empty lines in the second bit of code, but I got rid of most of them. Don't start identifiers with underscores.
And you have a bit of poor design, with public fields in the Employee class.
I think your Employee class first implement, comparable interface. Then in your heap sort methods you will pass an array of Comparable.
Also it would be easier if you start putting elements from index 1.
Like parent of the any number will be at (k / 2) position and childrens are 2k and 2k+1 position where k is index if you use index = 1.