I remember thinking of learning Tcl for a project. I bought a book (this was practically pre-web) and very early on it said not to use arrays, as they were O(n) access time. So I gave up.
"arrays" are hash tables. You'd use the built in lists where you'd use an array in C. In 8.5, Tcl has "real", first class hash tables, "dicts", which, as I mention in the article, took too long to show up in the language.
