I'd like to translate a character in Emacs to its numeric ascii code, similar to casting char a = 'a'; int i = (int)a in c. I've tried string-to-number and a few other functions, but none seem to make Emacs read the char as a number in the end.
What's the easiest way to do this?
String is an array.
(aref "foo" 0)
To get the ascii-number which represents the character --as Drew said-- put a question mark before the character and evaluate that expression
?a ==> 97
Number appears in minibuffer, with C-u it's written behind expression.
Also the inverse works
(insert 97) will insert an "a" in the buffer.
BTW In some cases the character should be quoted
?\" will eval to 34
A character is a whole number in Emacs Lisp. There is no separate character data type.
Function string-to-char is built-in, and does what you want. (string-to-char "foo") is equivalent to (aref "foo" 0), which is @abo-abo's answer --- but it is coded in C.
来源：https://stackoverflow.com/questions/19862517/emacs-lisp-getting-ascii-value-of-character