<?php
function getLastMessages($messages){
  $total = count($messages);
  $maxDisplayed = 3;
  if($total < $maxDisplayed){
    $displayed = $total;
  }else{
    $displayed = $maxDisplayed;
  }

  $start = $total - $displayed;
  $end   = $start + $displayed;
  $result = [];

  for($i = $start; $i < $end; $i++){
    $result[] = $messages[$i];
  };
  return ["messages"=>$result,"skipped"=>$total-$displayed];
}

$res = getLastMessages(["q","w","e","r","t","y","u"]);
echo "skipped: " . $res["skipped"] . "<br>";
foreach($res["messages"] as $msg){
    echo $msg . "<br>";
}