Explore JavaScript Data Types with getType Function

Introduction

This article covers the following tech skills:

In this lab, we will explore the concept of data types in JavaScript. We will learn how to use the getType function to determine the native type of any given value, whether it is undefined, null, or an instance of a constructor. By the end of the lab, you will have a solid understanding of how to work with different data types in JavaScript.

Function to Get Type of Value

To get the type of a value, use the following function:

const getType = (v) => {
  if (v === undefined) {
    return "undefined";
  }

  if (v === null) {
    return "null";
  }

  return v.constructor.name;
};

• The function returns 'undefined' or 'null' if the value is undefined or null.
• Otherwise, it returns the name of the constructor by using Object.prototype.constructor and Function.prototype.name.

Example usage:

getType(new Set([1, 2, 3])); // 'Set'

Summary

Congratulations! You have completed the Type of Value lab. You can practice more labs in LabEx to improve your skills.

---

🚀 Practice Now: Type of Value

---

Want to Learn More?

• 🌳 Learn the latest JavaScript Skill Trees
• 📖 Read More JavaScript Tutorials
• 💬 Join our Discord or tweet us @WeAreLabEx

Comments

[KooiInc]

But wait: getType(+("NaN")) => Number? getType(1/0) => Number?

This small module may be more useful.

[Jon Randy 🎖️]

You've missed BigInt from the primitive types