JS programowanie obiektowe. 1. JavaScript Programowanie Obiektowe Piotr Czajkowski [email protected]; 2. constructor new. Poznasz i zrozumiesz najnowsze mechanizmy JS (ES6+) Programowanie obiektowe z użyciem słów kluczowych class, extends itd. In the early nineties, a thing called object-oriented programming stirred up the software industry. Most of the ideas behind it were not really new at the time, but.

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Can you design a function methodwhich allows you to bind an object to one of its methods without naming the object twice?

JavaScript. Programowanie obiektowe

Quite a few times, I have found myself accidentally adding methods to a constructor instead of its prototype, or trying to call Array. Objects are turned to strings by calling their toString method, so giving objektowe own object types a meaningful toString is a good way to make them readable when printed out.

This means that javascript.provramowanie simple objects have a toString method, which converts them to a string. First, its constructor, which takes a plan an array of strings as argument, and initialises its grid. The property indicating what is above the bug is called “n”for North, the one obieitowe what is above and to the right “ne”for North-East, and so on. You could try to make the lichen-eater-eaters ‘hibernate’ use the “wait” action for a whilewhen they fail to find food for a few turns.

Modify the lichenPlan array to include a few of these, and try them out. It would also look better if, instead of printing a thousand terraria below each other, we could update a single printout of the terrarium.


In chapter 7 we used three functions, pointaddPointsand samePoint to work with points. Unfortunately, when a program starts to make serious use of inheritance, this approach to objects quickly becomes clumsy. When the point is at the edge of the grid, use ” ” for the directions that go outside of the grid, so the bug will not try to move there. Anyway, when you are done watching this fascinating show, shut it down:.

And if, at some point, you find that you really need it, you can search javascript.programowznie web, do some research, and figure out an approach that works for your situation. Another good solution is to use a function similar to partial from chapter 6. If, for example, we wondered whether there is a cat called “constructor”we would have checked it like this:.

Code which uses point objects may freely retrieve and modify x and y. These three functions form an interface for such objects.

For this, we will use two functions provided by the browser, called setInterval and clearInterval.

It returns a value that can be given to clearInterval to stop its effect. Of javawcript.programowanie, if you are careful, and you do not expect your code to have to coexist with badly-written code, adding methods to standard prototypes is a perfectly good technique. Note that it would be a bad idea to just do this.

Editions of Object-Oriented JavaScript by Stoyan Stefanov

It is part of the prototype jxvascript.programowanie a rabbit. We are interested only in the properties that the object itself has. Object-orientation’s longevity can largely be explained by the fact that the ideas at its core are very solid and useful.

We could just replace the method of to the Terrarium prototype, but we have become very attached to the simulation of the bouncing and drunk bugs, and we would hate to break our old terrarium. In fact there are, as usual, multiple good approaches to this. It takes an object with object and javascript.programownie properties, as returned by listActingCreaturesas argument. For each of the eight directions, it contains a property.


This argument can be used to specify the object that the function must be applied to. Fortunately, this terrarium-simulator is not required to be accurate in any way, so we can get away with it.

They obieitowe automatically inherit the constructor of their super-type. We can make a simple, stupid bug that always just goes south, ‘towards the light’, like this: Give the prototype of this constructor a method addwhich takes another point as argument and returns a new point whose x and y are the sum of the x and y of the two given points. When looking up the value of javascript.proggamowanie property, JavaScript first looks at the properties that the object itself has.

What I want to do is warn the reader against developing an unhealthy attachment to them. Using this, we could rewrite our properties method like this:. A better approach would be to store the characters and the corresponding bug-constructors in a dictionary, and look for them there: For that second problem, this page conveniently provides a function called inPlacePrinter.