How to use implode() and explode() in PHP?

explode() function breaks a string into an array, but the implode() function returns a series from the elements of an array.

Example :
$arr = array("1","2","3","4","5");

$str = implode("-",$arr);

OUTPUT

1-2-3-4-5

$array2 = "My name is umesh";

$a = explode(" ",$array2 );

print_r ($a);

OUTPUT

$a = Array ("My", "name", "is", "umesh");