get the value from for loop

I want to get the for loop value in php I have some names and I want to add '/'after each name and print the value outside the loop I want to get the $approver_name from for loop

foreach($co_practice as $co_practice_approver){
  // global $approver_name;
if($j>=1){
  $approver=users::where('id','=',$co_practice_approver)->first()->firstname;
  $approver_name=$approver_name. ' / ' .$approver; 

 }
else{
  $approver_name=users::where('id','=',$co_practice_approver)->first()->firstname;
}

 Hello 

via Chebli Mohamed