AutoCAD Tutorials

Mathematical expression formatAutoLISP uses a prefix notation for evaluating math expressions. The normal way you write equations is using an infix notation. If you wanted to add two numbers you would write it:1 + 2 = XIn AutoLISP it would be written as:(+ 1 2) ;Returns 3As you should know by now, all lists in AutoLISP start with a function and the remainder of the list is … [Read more...] about AutoLISP Lesson 6 – NUMBERS

(April 1999)An AutoLISP program can be written many ways, but there are certain structural points that are common to all programs. Here you will learn how to put together a program, structured in the manner that best suits your current application.One of the main differences between programming in AutoLISP and programming in other languages, is AutoLISP is an interpreted … [Read more...] about AutoLISP Lesson 4 – PROGRAM FORMAT

(April 1999)Variables are used as the principle means to store values. Files may also be used to store values, but variables are what store values for short-term use.AutoLISP variables may be any of (4) four "types"; integers, reals, points, or strings. Variables in AutoLISP are automatically "typed" depending on the value they contain, so no "typing" of variables is … [Read more...] about AutoLISP Variables Explained – Lesson 5 (Free Course)

(April 1999)Why comment? In the lifecycle of a program there will be times when it is necessary to make changes, comments should be viewed as a revision and quality control function. Comments should only be written to aid in the later modification of the program or to find out what version of a particular program or function is currently being used. A good comment states … [Read more...] about AutoLISP Lesson 3 – COMMENTS

(April 1999)The AutoLISP environment is entered when AutoCAD receives a "(" symbol at the command line. When AutoCAD sees the opening parentheses, it runs the AutoLISP interpreter. The interpreter then evaluates, as a list, what is between the opening "(" symbol and the closing ")" symbol.Data typesThere are three basic data types in AutoLISP. They are functions, symbols, and … [Read more...] about AutoLISP Lesson 2 – THE AutoLISP ENVIRONMENT

(April 1999)AutoLISP is a dialect of the LISP programming language (LISt Processing). LISP is the oldest high-level programming language, second only to FORTRAN. LISP has been the language of choice for the artificial intelligence in robotics. It is built into AutoCAD.What is a program? A program is a list of instructions for your computer to carry out.What you need? To program … [Read more...] about AutoLISP Lesson 1 – Introduction to Lisp Programming