Получите первый элемент массива php
array_values($array)[0];
Sparkling Swan
array_values($array)[0];
$colors = array(2=>"blue",3 =>"green",1=>"red");
$firstValue = reset($colors); //blue
$firstKey = key($colors); //2$dis=$mysqli->query("select * from article");
while ($diss = $dis->fetch_assoc()) {
$t=$diss['title'];
$abbreviation = explode(' ', trim($t ))[0];
echo $abbreviation;
echo'</br>'; // will print Hello
}