- print_r: documentation ( source)
- array_merge: documentation ( source)
<?php
$params = array('name' => 'Test', 'age' => 20);
$field = 'id';
$value = 2;
$where = array_merge($params, array("'".${$id}."'" => $value));
echo '<pre>';
print_r($where);
echo '</pre>';