Use of undefined constant ARRAY_FILTER_USE_BOTH - assumed 'ARRAY_FILTER_USE_BOTH'

Question

I use Codeigniter as the framework and create an array like below using input parameters from a form.

$data           = array(
    'generated_id'      => $this->input->post('generated_id'),
    'one'               => $this->input->post('one'),
    'two'               => $this->input->post('two'),
    'three'             => $this->input->post('three'),
    'modified_date'     => date('Y-m-d H:i:s'),
    'modified_user_id'  => $this->session->userdata('user_id')
);

What I want to do is if the value from the input fields are empty I want to set the value of the particular array position to NULL. I'm using below function to get it done.

$data = array_filter($data,function($value, $key){
    if(empty($value))
        return NULL;
    else
        return $value;
}, ARRAY_FILTER_USE_BOTH);

But I end up with below error.

Use of undefined constant ARRAY_FILTER_USE_BOTH - assumed 'ARRAY_FILTER_USE_BOTH'

Is there an easy way to get this done or how can I fix this?

Answer 1

Since you're not using $key in your callback at all, you do not need the ARRAY_FILTER_USE_BOTH flag either. Your function can be simplified to:

$data = array_filter($data);

Seriously, it does the same thing.

What I want to do is if the value from the input fields are empty I want to set the value of the particular array position to NULL.

array_filter won't do that to begin with. It will completely remove "empty" elements, not set them to null. You want:

$data = array_map(function ($value) { return $value ?: null; }, $data);

This will set any values which are falsey (empty strings, 0, empty arrays) to null.