const js - Javascript

Introduction

JavaScript is a widely used programming language that is popular among web developers. One of its features is const, which is used to declare a constant variable.

What is const?

const is a keyword in JavaScript that is used to declare a variable that cannot be re-assigned. The value of a constant variable cannot be changed once it has been initialized.

const PI = 3.14159;

In the code snippet above, PI is a constant variable that has been assigned the value of 3.14159. This value cannot be changed.

Benefits of using const

Using const has several benefits:

1. It helps prevent accidental re-assignment of variables.
2. It improves the readability of code as readers can identify which variables are meant to be constant.
3. Constants are usually optimized by the JavaScript engine, resulting in faster code execution.

When to use const

Use const when you want to declare a variable that should not be re-assigned. Some common examples include:

• Mathematical constants (e.g. PI, E, etc.)
• API keys or authentication tokens that should not be changed
• Configuration settings that should not be modified

Conclusion

const is a powerful feature of JavaScript that can help you write clean, concise, and bug-free code. By using const, you can ensure that your variables are not accidentally re-assigned, and improve the overall readability of your code.