$array = array(0=>'PHP', 1=>'c', 2=>"java", 3=>"c++");
print_r($array);
unset($array[2]);
print_r($array);
$array = array_values($array);
print_r($array);
/*
run:
Array
(
[0] => PHP
[1] => c
[2] => java
[3] => c++
)
Array
(
[0] => PHP
[1] => c
[3] => c++
)
Array
(
[0] => PHP
[1] => c
[2] => c++
)
*/