for ($i = 0; $i < 10; $i++)
{
    // do something
}

while ($result = $db->fetch_array($results))
{
    // do something
}

if ($condition != 'something')
{
    // do something
}

foreach ($array AS $key => $val)
{
    // do something
}

if ($condition)
{
    // do something
}
else if ($condition_two)
{
    // do something else
}