Decoding JavaScript’s Elegance: Understanding Default Parameters

Enhance Code Clarity and Simplicity with Practical Default Parameter Examples

Photo by Pawel Czerwinski on Unsplash

In the realm of JavaScript, simplicity often reigns supreme, and one feature that exemplifies this principle is default parameters.

In this article, we’ll demystify default parameters, showcasing how they contribute to clean and readable code.

Unveiling Default Parameters: The Basics

Default parameters offer a straightforward way to assign default values to function parameters. This ensures that even if a parameter is not explicitly provided when the function is called, it won’t result in undefined values. Let’s explore the basics with some practical examples.

1. Basic Usage of Default Parameters

Consider a simple function that calculates the area of a rectangle:

// Without default parameters
function calculateRectangleArea(length, width) {
  length = length || 0;
  width = width || 0;
  return length * width;
}

console.log(calculateRectangleArea(5, 4)); // Output: 20
console.log(calculateRectangleArea(5));    // Output: 0 (width is undefined)