Cutting characters in a variable

Shell Programming and Scripting
1

I have a variable var which contains "ABCDEFDH"
Now I have to remove the first 4 characters that is "ABCD"
so my variable should contain only "DEFH"
plzz tell me how to do that .
i am using bash shell

2

Homework ?..

anyway , something like this :

echo "ABCDEFDH" | cut -c5-8