Foreach loop echo - php

Question

The last foreach loop doesn't seem to echo the list I want, it doesn't print anything. How can I fix this? I know it's getting quite complicated but any help would be appreciated.
$allTroopsList = array();
$allMissionsList = array();
while ($mytroops = $alltroops->fetch_assoc())
{
$allTroopsList []= $mytroops;
}
while ($mymissions = $allmissions->fetch_assoc())
{
$allMissionsList []= $mymissions;
}
while($userintroop = $allUsersintroops->fetch_assoc())
{
if($userintroop['userid'] == $_SESSION['userid'])
{
echo "<ul class='troop'>";
echo "<li>" . $userintroop['troopid']. " </li>";
foreach($allTroopsList as $mytroops)
{
if($userintroop['troopid'] == $mytroops['troopid'])
{
echo "<li> Troop description: " . $mytroops['description']. " </li>";
foreach($allMissionsList as $mymissions)
{
if($mytroops['missionid'] == $mymissions['missionid'])
{
echo "<li> Missionname: " . $mymissions['missionname']. " </li>";
echo "<br/>";
echo "</ul>";
}
}
}
}
}
}
foreach($allUsers as $myotherusers)
{
if($userintroop['userid'] == $myotherusers['userid'])
{
echo "<li> other users: " . $myotherusers['username']. " </li>";
echo "<br/>";
}
}

Answer 1

This line:
while($userintroop = $allUsersintroops->fetch_assoc())
is fetching results from a database, right? That'd mean at some point you run out of rows to fetch, and $userintroop will become a boolean FALSE.
Then later on you try to do
if($userintroop['userid'] == $myotherusers['userid'])
which is wrong on two levels - $userintroop will NOT be an array at this point, so it could never have a ['userid'] parameter. And since it's the result of a failed fetch operation, never could have any value OTHER than a FALSE.
So that last loop does execute, but will never produce anything since the conditions for producing output are literally impossible to meet.