Thank you all for taking your time and replying my previous post.
Now I have other questions: 1) After I write a class with some methods I
want to save the file called test. Which extension is associated with
this file(test.rb or else)? How do I create a new object from the file
called test from another script? (I check the online book of programming
Ruby but just can’t find information yet)
2)Which method is used globally for the following substitution ?
s1=“AATTCCGG” # original string
s2=“TTAAGGCC” # expected string, which means A->T, T->A, C->G, G->C