How to make number automatically in the Constructor java
<p>I got two constructors : </p>

<pre><code>private int num ;
private Room room ;
private boolean status;
private E_types type ;
</code></pre>

<p>1- : Partial Constructor : </p>

<pre><code>Instrument(int num)
Partial Constructor ~ use for initial key fields
</code></pre>

<p>2- : Full Constructor : </p>

<pre><code>Instrument(Room room, boolean status, E_Types type)
Full Constructor ~ use for initial all fields instruments should be numbered automatically
</code></pre>

<p>What is this automatically numbered ? </p>

<p>Thanks :) </p>