- array_map: documentation ( source)
- var_export: documentation ( source)
- implode: documentation ( source)
<?php
$input = [
['01','03','02','15'],
['05','04','06','10'],
['07','09','08','11'],
['12','14','13','16'],
];
var_export(
implode(
'|',
array_map(
fn() => implode(',', func_get_args()),
...$input
)
)
);