How to make Debian package install dependencies?

Question

I want to make a simple Debian package to install a simple tool that depends on Qt4 libs.

In control file I have defined that it depends on Qt4 libs however, by the time

Answer 1

Per @textshell in this answer:

starting with apt 1.1 (available in Xenial (16.04), stretch) apt install also allows local files:

sudo apt install ./foo-1.2.3.deb

So much simpler and cleaner.

See the release announcment

This will also install dependencies, just like a normal apt install or apt-get install.