implode < PHP
The implode function joins an array of elements with a separator into a string. Explode() does the opposite.
$words = array('This', 'is', 'one', 'small', 'step');
$string = implode(' ', $words);
echo $string;
// This is one small step
$parts = [127,0,0,1];
$ip = implode(".", $parts);
echo $ip;
// 127.0.0.1