[BUG] Fix LGTM/CodeQL alerts

Description

There are 10+ CodeQL alerts on the whole repository. This should be fixed immediately.

Expected behavior

CodeQL/LGTM alerts should be fixed.

Actual behavior

We have 10+ CodeQL/LGTM alerts.

Possible fix

No response

Steps to reproduce

Not applicable here, IMO.

Context

This makes our code less elegant and professional. We should try to use the best code possible.

Additional information

Anyone who wants to work on this, feel free to do so. Just make sure you comment here before working on the issue.