JavaScript Error handling, “try…catch”
No matter how great we are at programming, sometimes our scripts have errors. They may occur because of our mistakes, an unexpected user input, an […]
JavaScript
JavaScript Mixins
In JavaScript we can only inherit from a single object. There can be only one [[Prototype]] for an object. And a class may extend only one other […]
JavaScript Class checking: “instanceof”
The instanceof operator allows to check whether an object belongs to a certain class. It also takes inheritance into account. Such a check may be necessary in […]
JavaScript Extending built-in classes
1. Overview Built-in classes like Array, Map and others are extendable also. For instance, here PowerArray inherits from the native Array: Please note a very interesting thing. Built-in […]
JavaScript Private and protected properties and methods
One of the most important principles of object oriented programming – delimiting internal interface from the external one. That is “a must” practice in developing […]
JavaScript Class inheritance
Class inheritance is a way for one class to extend another class. So we can create new functionality on top of the existing. 1. The […]
JavaScript Class basic syntax
In object-oriented programming, a class is an extensible program-code-template for creating objects, providing initial values for state (member variables) and implementations of behavior (member functions or methods). […]
JavaScript Native prototypes
The “prototype” property is widely used by the core of JavaScript itself. All built-in constructor functions use it. First we’ll see at the details, and then how […]
JavaScript F.prototype
1. Overview Remember, new objects can be created with a constructor function, like new F(). If F.prototype is an object, then the new operator uses it to set [[Prototype]] for the new […]
JavaScript Prototypal inheritance
In programming, we often want to take something and extend it. For instance, we have a user object with its properties and methods, and want to make admin and guest as […]
JavaScript Property getters and setters
There are two kinds of object properties. The first kind is data properties. We already know how to work with them. All properties that we’ve been […]
JavaScript Property flags and descriptors
As we know, objects can store properties. Until now, a property was a simple “key-value” pair to us. But an object property is actually a […]
JavaScript Arrow functions revisited
Let’s revisit arrow functions. Arrow functions are not just a “shorthand” for writing small stuff. They have some very specific and useful features. JavaScript is […]
JavaScript Function binding
When passing object methods as callbacks, for instance to setTimeout, there’s a known problem: “losing this“. In this chapter we’ll see the ways to fix it. 1. […]
JavaScript Decorators and forwarding, call/apply
JavaScript gives exceptional flexibility when dealing with functions. They can be passed around, used as objects, and now we’ll see how to forward calls between them and decorate them. […]
JavaScript Scheduling: setTimeout and setInterval
We may decide to execute a function not right now, but at a certain time later. That’s called “scheduling a call”. There are two methods […]
JavaScript The “new Function” syntax
There’s one more way to create a function. It’s rarely used, but sometimes there’s no alternative. 1. Syntax The syntax for creating a function: The […]
JavaScript Function object, NFE
As we already know, a function in JavaScript is a value. Every value in JavaScript has a type. What type is a function? In JavaScript, […]
JavaScript Global object
1. Overview The global object provides variables and functions that are available anywhere. By default, those that are built into the language or the environment. […]
JavaScript The old “var”
This article is for understanding old scripts The information in this article is useful for understanding old scripts. That’s not how we write a new […]
