title: Message: implode(): Invalid arguments passed if checkbox value doesn't have any record or empty
body: <p>When adding records into the database. Some fields are shows as per selection that time some checkbox fields are not displayed. Then pass values is empty.</p>
  
  <pre><code>$data = array(
          'pro_name'=&gt;$this-&gt;input-&gt;post('pro_name'),
          'c_id'=&gt;$this-&gt;input-&gt;post('c_id'),
          's_id'=&gt;$this-&gt;input-&gt;post('s_id'),
          'pro_price'=&gt;$this-&gt;input-&gt;post('pro_price'),
          'c_name'=&gt;$c_name,
          's_name' =&gt; $s_name,
          'power_consumption'=&gt;$this-&gt;input-&gt;post('power_consumption'),
          'model'=&gt;$this-&gt;input-&gt;post('model'),
          'type'=&gt;$this-&gt;input-&gt;post('type'),
          'cutout_size'=&gt;$this-&gt;input-&gt;post('cutout_size'),
          'cct' =&gt; substr(implode(', ', $this-&gt;input-&gt;post('cct')), 0),  
          'feet' =&gt; substr(implode(', ', $this-&gt;input-&gt;post('feet')), 0),         
          'p_application' =&gt; substr(implode(', ', $this-&gt;input-&gt;post('p_application')), 0),  
          'p_desc'=&gt;$this-&gt;input-&gt;post('p_desc'),
          'pro_status'=&gt; '5'
      );
      //print_r($data); die();
      $this-&gt;db-&gt;insert('product',$data);
  </code></pre>
  
  <p>if cct column is not present in my form as per selection of field then it set the value to 0 or remove </p>
  
  <blockquote>
    <p>Message: implode(): Invalid arguments passed.</p>
  </blockquote>