Dynamic Variable Naming in JavaScript: Techniques and Best Practices

In programming, especially in languages like JavaScript, dynamic variable naming can be both a powerful and a challenging feature to utilize effectively. While direct usage of string content as variable names is not supported, several methods can achieve similar functionality. This article explores various approaches and best practices for dynamic variable naming in JavaScript.

Introduction to Dynamic Variable Naming

JavaScript does not support the direct use of string content as variable names in the same way as some other languages might. However, you can achieve comparable functionality using objects or the `window` object in a browser environment. This article will delve into common methods to achieve dynamic variable naming and their use cases.

Method 1: Using Objects

One of the most common and safe methods to achieve dynamic variable naming is through the use of objects. By storing values as dynamic keys in an object, you can manipulate and access these values dynamically.

const variables  {};
const variableName  'myVariable';
variables[variableName]  'Hello World!';
console.log(variables[variableName]); // Output: Hello World!

This method is both safe and clean, making it a preferred choice for most use cases.

Method 2: Using the `window` Object (Browser Environment Only)

In a browser environment, you can add properties to the `window` object, which represents the global scope. This approach is useful when you need to create dynamic global variables.

const variableName  'myVariable';
window[variableName]  'Hello World!';
console.log(window[variableName]); // Output: Hello World!

Note that this method is specific to the browser environment and should be used with caution in other contexts.

Method 3: Using `eval` (Not Recommended)

While you can use `eval` to create variables dynamically, it is generally discouraged due to security and performance concerns. The use of `eval` can lead to potential risks and should be avoided unless absolutely necessary.

const variableName  'myVariable';
eval(`var ${variableName}  'Hello World!';`);
console.log(myVariable); // Output: Hello World!

This method, although functional, is not recommended due to its potential risks and performance issues.

Creating Classes and Functions Based on String Content

Another common scenario is dynamically naming classes or functions based on string content. For example, if you have a Model class that represents database access and you want to use it for accessing different collections (such as User, Group, or AccessRights), you might need to dynamically name each class.

Example 1: Using a String Variable to Name a Class or Function

A common and straightforward way to achieve this is by using the method:

function create_class_with_name(name) {
    return { [name]: class {
        show() {
            console.log(`Self name: ${}`);
        }
    } }[name];
}
let nameOfMyClass  'MyClass';
let myClass  create_class_with_name(nameOfMyClass);
let inst  new myClass;
//  new MyClass

In this example, the class is dynamically named based on the string content passed to the `create_class_with_name` function.

Example 2: Using an Object to Store and Access Classes Based on a Name

Alternatively, you can use an object to store multiple classes with dynamic names:

let my_vars  {};
my_vars[nameOfMyClass]  class {
    show() {
        console.log(`Self name: ${}`);
    }
};

This approach is more flexible and maintainable, especially when dealing with multiple classes.

Conclusion

Dynamic variable naming in JavaScript can be achieved using objects, the `window` object, or the `eval` function. However, it is essential to choose the method that best fits your specific use case and to prioritize security and performance. Objects and the `window` object provide safe and clean alternatives.

When creating classes or functions dynamically based on string content, consider using the method or an object to store and access classes with dynamic names. These methods offer more flexibility and maintainability, making them superior choices for most scenarios.