When we use - and when we use -- in docker RUN??

Docker
#1

When we use - and when we use – in docker RUN??

example for name we use “–name webapp”
and for environment variable we use “-e APP_COLOR=blue”

Is it like if - then we use =
            if it is -- then we use just space to assign value??
#2

Hello, @amar6969
That’s not the case, it just a short form of –env. You are assigning a value to APP_COLOR variable that’s why adding equal sign.

docker run --name=webapp nginx

docker run --name webapp nginx

Both is same.