How Do You Create Constructor-like Behavior in JavaScript Without Native Classes?

JavaScript Object Constructors

In JavaScript, unlike other programming languages, classes and objects do not have native constructors. Instead, they employ alternative methods to achieve similar functionality.

Using Prototypes

One way to create a constructor-like behavior is through prototypes. A constructor function can be defined, such as Box(color), where this refers to the object being created. The constructor initializes the object's properties, such as color.

Additionally, prototypes allow for the creation of shared methods. The Box function can define a getColor method within its prototype, which can be accessed by all objects created using Box.

Hiding Properties

Alternatively, it is possible to hide properties within an object to simulate private member variables. A function can be defined with a private variable color, and expose a getColor method to retrieve its value.

Usage

Both approaches enable the creation of instances using the new keyword. For example, new Box("blue") and new Box("green") create two separate instances with different values for color. Calling getColor on these instances will return their respective colors.

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