To convert an array to a string in PHP, you can use the implode() function. The implode() function joins the elements of an array into a single string with a specified separator.
Here's an example:
$array = array('Hello', 'world', '!');
$string = implode(' ', $array);
echo $string; // Output: Hello world !
In this example, the implode() function is used to join the elements of the $array array into a single string separated by a space. The resulting string is stored in the $string variable and then outputted using echo.