Codeigniter中的Multiple Select框返回字符串而不是值数组

Question

I am getting a strange behaviour.

In a view in Codeigniter I have this code:

<?php echo form_multiselect('post-categories', $active_categories, (!empty($selected_categories))?$selected_categories:null,array('class'=>'form-control')); ?>

Which generates the following HTML

<select name="post-categories" class="form-control" multiple="multiple">
<option value="1">Beauty</option>
<option value="4">More</option>
<option value="3">New</option>
</select>

However when I submit the form with multiple categories selected I receive only strings.

In the controller

var_dump($this->input->post('post-categories'));

will output

string(1) "3"

Is there something I am doing wrong or missing?

Answer 1

The name should be post-categories[] (array syntax). Try -

form_multiselect('post-categories[]', $active_categories, (!empty($selected_categories))?$selected_categories:null,array('class'=>'form-control'));