PHP us a string variable as an argument for function

I am trying to set a variable as a string and then use that variable in a while loop function.

<?php
$assoc = <<<'EOF'
$users[]=array('name'=> $row['name'], 'foreman_position'=> $row['foreman_position'], 'status'=> $row['status'], 'emp_num'=>$row['employee_num'],'sen_num'=> $row['seniority_num']);
EOF; 


  while($row = mysqli_fetch_assoc($result)) {
      echo $assoc;

   }

When evaluated I would like it to look like this:

while($row = mysqli_fetch_assoc($result)) {   
     $users[]=array('name'=> $row['name'], 'foreman_position'=> 
     $row['foreman_position'], 'status'=> $row['status'], 'emp_num'=>   
     $row['employee_num'],'sen_num'=> $row['seniority_num']);
   }

If I put the syntax in by hand it works fine but the variable is expressing as the string. Any help is greatly appreciated.

That is just not how this works. If you want to make a piece of code reusable or just move it elsewhere, you use functions:

function extractResult(array $row, array &$output) {
    $output[] = [... => $row[...], ...];
}

$users = [];

while ($row = mysqli_fetch_assoc($result)) {
    extractResults($row, $users);
}