user62045: I have received the bitcoin way back in 2013 in Bitcoin Core. At that time I don't know about the importance of wallet.dat - I have formatted my hard disk and install Bitcoin Core again in 2017 but there it didn't show my Bitcoin in my balance. I have my Bitcoin Key.
I meant "Bitcoin Key" is my Public Key on which I got my bitcoin. Is there any other way to get my Bitcoin back if I didn't get my original wallet.dat of Bitcoin Core?
How can I get my bitcoin back?
How can I get to know my Private Key?

user13866: Your money is lost without at least one of

a backup of important data from the hard disk before it was formatted
a backup of the wallet.dat file
a note of the private key

There is no way to recover the private key from other information. If there was, Bitcoin would be completely unsafe and unusable.

62045: <p>I have received the bitcoin way back in 2013 in Bitcoin Core. At that time I don't know about the importance of wallet.dat - I have formatted my hard disk and install Bitcoin Core again in 2017 but there it didn't show my Bitcoin in my balance. I have my Bitcoin Key.</p>
<p>I meant &quot;Bitcoin Key&quot; is my Public Key on which I got my bitcoin. Is there any other way to get my Bitcoin back if I didn't get my original wallet.dat of Bitcoin Core?</p>
<p>How can I get my bitcoin back?<br />
How can I get to know my Private Key?</p>
 13866: <p>Your money is lost without at least one of</p>
<ul>
<li>a backup of important data from the hard disk before it was formatted</li>
<li>a backup of the <code>wallet.dat</code> file</li>
<li>a note of the private key</li>
</ul>
<p>There is no way to recover the private key from other information. If there was, Bitcoin would be completely unsafe and unusable.</p>
