How to cast a character to int in Clojure?

Question

How to cast a character to int in Clojure?

I am trying to write a rot 13 in clojure, so I need to have something to cast my char to int. I found something called (in

Answer 1

What you are looking for is a character literal \a. A character literal is denoted by a single character, or 16-bit unicode code point, prefixed by the \ reader macro.

(int \a) ;; => 97

(int \0) ;; => 48

(int \u0030) ;; => 48

With (int a), a is a symbol. As such, the runtime tried and failed to resolve what that symbol was bound to.

With (int 'a), a is also a symbol, but, because you declared it a symbol with the single quote ('), the runtime took it literally and tried and faild to cast the clojure.lang.Symbol to a java.lang.Character.

With (rot13 ''a'), 'a' declares a' as a symbol. But, the extra ' prefixing it makes the runtime treat the expression that declared the a' literally. 'a' expands to (quote a'), so the "literal literal", ''a', expands to the list (quote a').

''a' ;; => (quote a')

(second ''a') ;; => a'

With (rot13 "a"), a is a string. Strings cannot be cast to characters, but they can be treated as collections of characters. So, (rot13 (first "a")) would work as intended.