How Do I Make Javascript Object Using A Variable String To Define The Class Name

In JavaScript, creating objects using a variable string to define the class name can be a handy technique that allows for dynamic object instantiation based on user input or other runtime conditions. In this article, we'll explore how to achieve this by leveraging the power of JavaScript.

One way to create objects dynamically in JavaScript using a variable string to define the class name is by utilizing the concept of constructor functions. These functions act as blueprints for creating objects of a particular type. Let's walk through a simple example to demonstrate this concept:

function createObject(className) {
    return new window[className]();
}

function MyClass() {
    this.property = 'value';
}

const className = 'MyClass';
const obj = createObject(className);

console.log(obj.property); // Output: value

In the code snippet above, we define a `createObject` function that takes a className as an argument. This function then instantiates an object of the class specified by the className variable using the `new` keyword along with `window[className]` which accesses the global object's properties.

Another approach to achieve dynamic object creation in JavaScript is by using ES6 classes. Let's see how we can achieve the same result using the class syntax:

class MyClass {
    constructor() {
        this.property = 'value';
    }
}

function createObject(className) {
    return new window[className]();
}

const className = 'MyClass';
const obj = createObject(className);

console.log(obj.property); // Output: value

In this example, we define a class MyClass with a constructor that initializes a property with a specific value. The createObject function remains the same, allowing us to create an instance of the dynamic class as before.

To further enhance this technique, you can also pass arguments to the constructor function when creating objects dynamically. This can be useful for initializing object properties based on dynamic data. Let's extend our previous example to include constructor arguments:

class MyClass {
    constructor(arg) {
        this.property = arg;
    }
}

function createObject(className, arg) {
    return new window[className](arg);
}

const className = 'MyClass';
const argument = 'dynamic value';
const obj = createObject(className, argument);

console.log(obj.property); // Output: dynamic value

In this updated example, we modified the MyClass constructor to accept an argument, allowing us to pass a dynamic value when creating an instance of the class.

By utilizing constructor functions or ES6 classes in combination with dynamic string variables, you can create objects dynamically in JavaScript based on class names provided at runtime. This technique adds flexibility to your code and enables you to adapt to changing requirements seamlessly.