I need Output in this format:
$a = array('category_id',1);
Rewrite the array as
$a = array('category_id'=> "1 ");
As the serialised params are in the format
type:length:value, you need to pass 1 as a string.
s:2:"1" won't be possible as 1 has a length of
2. If you wan't a string of 2 length, maybe we can pass
<space> to acheive that.