How to throw an argument into a container?

Question

Docker

Hello everyone, I started studying a docker course and there is a task

When starting a container from this image without arguments, it should print the string ''Hello World!' and exit.
When starting the container with an argument, the string ''Hello !

Created Dockerfile

FROM ubuntu:14.04

ENTRYPOINT ["echo"]
CMD ["Hello Wordl!"]

Those. run
docker build -t test .
docker run --rm test
Outputs "Hello Wordl!"
docker run --rm test string
Displays "string
"
I ask you not to throw slippers, the documentation did not help, just like the whole Google.
Thank you in advance for your response.

Answer 1

FROM alpine
ENTRYPOINT [ "echo", "hello" ]
CMD [ "world" ]