$rus=array ( [0]=> "а" [1]=> "" [2]=> "в");
$eng=array ( [0]=> "Z" [1]=> "Y" [2]=> "C");
$burundi=array ( [0]=> "L" [1]=> "K" [2]=> "J");
<?php
$rus = ["а", "", "в"];
$eng = ["Z", "Y", "C"];
$burundi = ["L", "K", "J"];
foreach($rus as $key => $value){
if(!$value){
unset($rus[$key]);
unset($eng[$key]);
unset($burundi[$key]);
}
}
var_dump($rus, $eng, $burundi);
<?php
$rus = ["а", "", "в"];
$eng = ["Z", "Y", "C"];
$burundi = ["L", "K", "J"];
foreach($rus as $key => $value){
if(!$value){
array_splice($rus, $key, 1);
array_splice($eng, $key, 1);
array_splice($burundi, $key, 1);
}
}
var_dump($rus, $eng, $burundi);