Greenfoot examples of modularized code code#

So if visualisation doesnвЂ™t scale to expert-level programs, then at some point on the transition from beginner to expert, you will have to leave behind visualisation. (Greenfoot allows digging down through objects to visualise them, but after a point in scaling your program, it becomes unusable through sheer mass of data.) Add more than about three variables and itвЂ™s not going to work well. But add a thousand crabs to the world and the visualisation is ruined. So maybe this could be visualised - perhaps you could have it floating above the actor. But at some point you will probably need to introduce state to the actors - perhaps an internal counter of how many worms a crab is eaten. The location of sprites/actors and their rotation are implicitly visible, and usually the early examples deal with manipulating this visible state. At some point they are all going to become too much:Д«eginner systems like Scratch or Greenfoot are deliberately designed to visualise lots of state implicitly.

Greenfoot examples of modularized code code#

But how do you visualise an array of 100,000 elements, or the complete object graph in a program with 50,000 objects? You can think about collapsible/folding displays or clever visual compression, but at some point itвЂ™s simply not feasible to visualise your entire program: program code can scale up 1000-fold with the tweak of a loop counter, but visualisations are inherently limited in scale. ItвЂ™s quite easy to visualise an array of 10 elements, or show the complete object graph in a program with 5 objects. I propose that visualisation doesnвЂ™t scale to large programs.

If you are serious about creating a programming environment for learning, the number one thing you can doвЂ¦ is to show the data.ДЄll state must be eliminated or shownвЂ¦ An environment that does neitherвЂ¦ is irresponsible design, and disrespectful to the learner. If a programmer cannot see what a program is doing, she canвЂ™t understand it. The essay repeatedly makes consistent, strong statements about visibility: (The suggestion of labelling parameters does make a lot of sense in languages without named parameters - although you could avoid the need for this by just designing your beginnersвЂ™ language to use named parameters.) See Everything In summary: being that being able to read code straight off the page is a skill that is part of programming, and I believe is it one that you need to learn so early on that this labelling will not be useful. The above is the reason people invented mathematics. Carry on doing this until you have an accurate enough result. If this value is the same sign as the value obtained by evaluating the function at the left hand end-point overwrite the left hand endpoint with c otherwise overwrite the right hand end-point with c. Take the values of the two end-points of the interval, add them together and divide by 2 and call this value c, evaluate the function at the point c. Can you explain the mathematical formulae for the bisection method in english please?ДЄ. IвЂ™m reminded of this quote from an anonymous Q&A page at Kent: I can understand that the labels are a bit more approachable, but I worry that for most cases, they are not actually helpful, and very quickly end up unwieldy. The point of the notation is to express concisely and unambigiously what the program does. We wouldnвЂ™t have a mouse-over helper in Maths saying вЂќ вЂ+вЂ™ is the symbol meaning add two numbersвЂќ or in French saying вЂњJe means IвЂќ - you learn it early on, quite easily, and then youвЂ™re fine. One of the first things beginners do in any area is learn the terms, after which I believe the labelling of program constructs becomes annoying rather than helpful. One of the suggestions in the essay is to label lines of code to say what they do: In this post I provide a commentary to the essay, along this theme: I believe that visualisation is often good for beginners but not for experts, and therefore transitioning from being a beginner into being an expert involves moving beyond visualisations. We just need to take off our blindfolds to see where weвЂ™re firing. The essay draws together various ideas about visualisation and programs, with very polished examples of executing the ideas, and it does make a very strong coherent argument for its ideals: mainly, that we should get a lot better at visualising programs to help beginners. ItвЂ™s worth reading, as much for the presentation as the content (I say that to compliment the presentation, not to disparage the content). Bret Victor has written an essay entitled Learnable Programming that is already circulating quite rapidly.