What are some similarities between the film and the book of Into the Wild?

Well, if it is similarities that you are focusing on, you
might want to think about the way in which the film presents the life of Chris
McCandless in a similar fashion to the book. That is to say there are two time periods:
when Chris makes it to Alaska and then his life before Alaska. The film jumps between
these two linear time periods. Of course, one aspect the film does not cover is the own
incidents of John Krakauer and his own "into the wild" experience that he shares with
the readers of his book. I must admit, I thought that the film was quite a faithful
rendition of the life of Chris McCandless as revealed to us in the book. It shows how he
was able to connect with all kinds of people and also the way in which he was trying to
withdraw from society, trying to attain a kind of Emersonian solitary existence just
living off his own wits in the middle of nature.