<?php
<?php
$yourArray = [
'one',
'two',
'three',
'four',
'five',
'six',
'seven',
];
$chunkedArr = array_chunk ($yourArray, 2);
foreach ($chunkedArr as $key=>$val) {
$chunkedArr[$key] = implode (", ", $val);
}
print_r( implode(" | ", $chunkedArr ) );
string(42) "one, two | three, four | five, six | seven"