Logo (Programming Language)

By: Monique McTague

History An educational programming language designed in

1967 by Daniel G. Bobrow.

Logo was derived from the Greek logos meaning word or thought to distinguish itself from other programming languages that were primarily numbers, not graphics or logic.

Logo is remembered for its use of “Turtle Graphics” in which commands for moment and drawing produced line graphics or with a small robot called “turtle”.

The use of virtual Turtles allowed for immediate visual feedback and debugging of graphic programming.

What is Logo?

Is a multi-paradigm adaptation and dialect of a functional programming language.

Programming in Logo is done by adding to its vocabulary, teaching it new words in terms of words it already knows. In this way it's similar to the way people learn spoken language. Logo works with words and list. Numbers are words but are special because you can do arithmetic.

Logo is not case-sensitive but retains the case used for formatting. It is a compromise between a sequential programming language with block structures, and a functional programming language.

Logo Design

Logo goal was to create a math land where kids could play with words and sentences.

Most logos are 2D, implementations are interpreted, and this interactivity provides the user with immediate feedback on individual instructions, which support the learning process.

Error messages are given when logo does not understand a procedure. For example if you input “foward”, Logo will respond “I don’t know how to

foward” Types of different logo:

UCBLogo StarLogo NetLogo ObjectLogo MicroWorlds MicroSoftLogo

Logo Goals

MicroSoft Logo

Forward is one of Logo’s procedural words. In this case logo needed additional

information to go with forward.

Logo

Now when given the command “forward 100” the arrow now moves 100 steps forward.

Logo Extensibility

Logo programs are usually collections of small procedures. Procedures are defined by writing them in a text editor.

First you use the word “to” followed by the name of the procedure.

The following line(s) define the procedures actions.

Then the word “end” tells the program you are finished defining the procedure.

For example to draw a square we input:› to square› repeat 4[forward 50 right

90]› end

Logo Extensibility

Procedures can be built on top of one another.

For example we can now define a new procedure called flower using the square command.

to flowerrepeat 36 [right 10 square]end

Random Selection

In the logo language we can use a procedure called “pick” to randomly select a item from a list.

For example the procedure will be defined as who.

› to who› output pick[Knaust

Melissa Agamyrat Jennifer Susana Monique]

› End

Every time I enter who, a name is randomly selected.

Logo Arithmetic

Other programs ask for you two define if numbers are integers or real numbers before executing operations.

Logo takes care of that for you and just does the arithmetic.

In Logo you cannot input “3+4” because logo will tell you it does not know what to do with “7”

Adding the word “print” before the expression tells logo output the solution.

Arithmetic

Adding Print in front of an expression works for any operation that is given.

Manipulating words and numbers

Print word "apple "sauceapplesauce

Print word "3 "434

Print 12 + word "3 "446

Print reverse [apples and pears] pears and apples

Conclusion

Logo is a child friendly program used for constructive learning.

Depending on the type of Logo program you use you can do animations and so much more procedures.

For example factorials and adding words to graphics.

The EndQuestions?References

Logo (Programming Language). (n.d.). Retrieved March 10, 2014, from Wikipedia: http://en.wikipedia.org/wiki/Logo_(programming_language)Tempel, M. (2012). The Logo Programming Language. Retrieved March 11, 2014, from Logo Foundation: http://el.media.mit.edu/logo-foundation/logo/programming.html