Why is the function being called from the current namespace?

Question

Yii

There is a project on Yii2. Everything worked great. until I updated Yii. Now I am getting this error.

'yii\base\ErrorException' with message 'Call to undefined function yii\db\ctype_digit()' in /var/www/rowcash/public_html/vendor/yiisoft/yii2/db/QueryBuilder.php:832

For some reason, the ctype_digit() function is called from the yii\db\ namespace and not from the global one.
PHP 5.5.22
Yii 2.0.4

Answer 1

Problem solved. It was my fault. The ctype extension was not installed.

Answer 2

\ctype_digit();