Emacs Lisp Basics

This page is a short, practical, tutorial of Emacs Lisp the language.

To evaluate elisp code, for example, type (+ 3 4), then move your cursor to after the closing parenthesis, then Alt+x eval-last-sexp Or, select the lisp code, then Alt+x eval-region. [see Evaluate Emacs Lisp Code]

To find the doc string of a function, Alt+x describe-function then type the function name. [see Documentation Lookup]

To turn on syntax highlight, Alt+x emacs-lisp-mode.

Printing

; printing
(message "hi")

; printing variable values
(message "Her age is: %d" 16)        ; %d is for number
(message "Her name is: %s" "Vicky")  ; %s is for string
(message "My list is: %S" (list 8 2 3))  ; %S is for any lisp expression

You can see the output in the Messages Buffer.

[see Print, Output]

[see Format String]

Arithmetic

• Arithmetic

Convert Int/Float/String

• Convert Int/Float/String

True, False

• Boolean

Test Equality

• Test Equality

Variables

• Variable

Block of Expressions

• Block of Expression

If Then Else

• If then else (Conditional)

Loop, Iteration

• Loop

Data Structure: List, Vector

• Vector
• List

String Functions

• String Functions

Format String

• Format String

Define a Function

• Define Function