how to validate array value in codeigniter

It doesn't let me submit the form If so, It sounds like a bug.

Temporarily, you can check whether duration[] array is empty or not:

if (! empty($_POST['duration'])) {    $this->form_validation->set_rules('duration[]',"Duration", "trim|xss_clean|numeric");}

I'll update my answer if I found the main solution.

Update:This is a bug as I expected, I opened a PR at CodeIgniter Repository, that would fix this issue.

So as suggested by @ Hashem Qolami I did the following changes in my code and it worked.

$organization    = $this->input->post('organization');$department      = $this->input->post('department');$positions       = $this->input->post('positions');$duration        = $this->input->post('duration');foreach($organization as $ind=>$val) {    $org  = $organization[$ind];    $dept = $department[$ind];    $pos  = $positions[$ind];    $dura = $duration[$ind];    $this->form_validation->set_rules("organization[".$ind."]", "Organization", "trim|xss_clean|max_length[1]");    $this->form_validation->set_rules("department[".$ind."]", "Department", "trim|xss_clean|max_length[50]");    $this->form_validation->set_rules("positions[".$ind."]", "Position", "trim|xss_clean|max_length[40]");    if(!empty($dura))       $this->form_validation->set_rules("duration[".$ind."]", "Duration", "trim|xss_clean|integer");}

and displayed my errors as follows

 for($i = 0; $i < count($organization); $i++) {     echo form_error("organization[".$i."]");      echo form_error("department[".$i."]");      echo form_error("positions[".$i."]");      echo form_error("duration[".$i."]");  }