Comma separated list from array with “and” before last element

Question

I have an array ($number_list) that has a dynamically generated list of values. There will be at least 1 value in the array and no more than 4.

Currentl

Answer 1

# pop the last element off the array and formate text
if( count( $number_list )>1 ){
    $and = " and ".array_pop( $number_list );
}else{
    $and = '';
}
# Implode number list , and  append $and
$comma_list = implode(', ', $number_list).$and;