The  implode() or join() is a built-in function in PHP and it is used for creating a string by joining the elements or values of an array with a glue string like hyphen (-) or comma (,).

Syntax:

implode(separator,array)

separator – This parameter is Optional. It Specifies what to put between the array values or elements. Default is “” (an empty string).

array – This parameter is required. The array to join to a string.

Example:

<?php
$array = array("HTML", "CSS", "PHP");
 
// Turning array into a string
$str = implode(", ", $array);
echo $str; // Outputs: HTML, CSS, PHP
echo '<br>';
$str = implode(" - ", $array);
echo $str; // Outputs: HTML - CSS - PHP
?>