Array to string conversion

[eluser]nirbhab[/eluser]
dude as far as my understanding is concerned $key is an Array().

Code:

if( ! empty($key['name']))

check this piece of code.
This is Array() for sure.
Please check the CI User Guide, there is a function do_upload().
Call this function in for loop for multiple uploading.

Code:

$config['upload_path'] = './uploads/';
        $config['allowed_types'] = 'gif|jpg|png';
        $config['max_size']    = '100';
        $config['max_width']  = '1024';
        $config['max_height']  = '768';
        
        $this->load->library('upload', $config);

Don't use this piece of code again and again, as this one is loading the upload library.
Load upload library once with its configurations.