how to unset array key and value?

If these 3 arrays are the content of one array, let's call it $array:

array_pop($array);

Will remove the last one, and optionally return it's value.

array_pop — Pop the element off the end of array

http://php.net/manual/function.array-pop.php

This does the same thing as unset() here, but for curiosity's sake, here's another way:

// Move the pointer to the last element
end($array);

// Get the key of the element
$key = key($array);

// Unset the item
unset($array[$key]);

Just use array_pop() though, the other method was for entertainment purposes only, but you could use it if you want to change the last element's value.

Demo: http://codepad.org/UFjal89X

Some reference:

key(): http://php.net/manual/function.key.php

end(): http://php.net/manual/function.end.php

try this ( if i understand your problem)

 $output =array();
 foreach($input as $k=>$v){
    if(!empty($v)){ 
        $output[$k]=$v;
    }
}

WORKING DEMO