PHP add +1 in while loop

Question

I have while loop and in that there's forum posts.I want to show number of posts (1,2..).

Let me show you what i think

while($some = mysql_fetch_array($forum_posts)){
echo 'Number of post is $num++';
}

and show like

------ Thread -------

------ Posts -------

Text of post            1.
Text of post            2.
Text of post            3.

Thanks.Sorry for bad english

Answer 1

$num must be initialized!

$num = 1;
while($some = mysql_fetch_array($forum_posts)){
echo 'Number of post is '.($num++);
}

Answer 2

$num = 0;

while($some = mysql_fetch_array($forum_posts)){
    echo 'Number of post is '.++$num;
}