php join

$arr = array('Hello','World!','Beautiful','Day!');
echo join(", ",$arr);

<?php

$arr = array('Hello','World!','Beautiful','Day!');

echo join(" ",$arr);

?> 

Definition and Usage
The join() function returns a string from the elements of an array.

The join() function is an alias of the implode() function.

Note: The join() function accept its parameters in either order. However, for consistency with explode(), you should use the documented order of arguments.

Note: The separator parameter of join() is optional. However, it is recommended to always use two parameters for backwards compatibility.

Syntax
join(separator,array)
  
Example
Join array elements with a string:

<?php
$arr = array('Hello','World!','Beautiful','Day!');
echo join(" ",$arr);
?>
  
Output:
Hello World! Beautiful Day!

<?php
$arr = array('Hello','World!','Beautiful','Day!');
echo join(" ",$arr);
?>