Using Arrays as Field Names

[eluser]moleculezz[/eluser]
Hello,

I have a small problem using arrays as field names. It doesn't seem to work. I checked the user guide and came up with the following method of doing it.
Form validation

Code:

<input type="text" name="options[]" value="<?php echo set_value('options[]'); ?>" size="50" />

When I submit the form. The fields are populated but with the word array.
I also tried the following, but that doesn't populate at all.

Code:

<input type="text" name="options[<?php echo $num;?>]" value="<?php echo set_value('options['.$num.']'); ?>" size="8"  />

I am using a for loop to display multiple input fields.