Drupal: Make single checkbox a required field

This CodeLet will make a single checkbox a require field. This is usefule when you are creating a checkbox in your custom module.

CodeLet: 

<?php
$form['terms_condition'] = array(
'' => 'checkboxes',
'' => t('Terms & condition'),
'' => array(
1 => t('I agree to Terms & condition'),
),
'' => TRUE,
);
?>

Is CodeLet useful?: 

Compatibility:

Image: 
Make single checkbox a required field in Drupal | Drupal Developer