Useful array map

Here is an example of array_map function to produce a string by appending each content of a flat array.

<?php
$the_ids = [1,2,3,4];
echo implode(' OR ', array_map( function($id){ return 'id=' . $id; }, $the_ids ) );

Produces the following output: id=1 OR id=2 OR id=3 OR id=4

This can be useful when trying to pass a where condition on a sql.