Truthy and Falsy Values in Javascript

js.Srijan

Table of Contents

Falsy Values

Most of the values in javascript are Truthy, so it is better to list the Falsy value where we have only a limited number of cases. There are a total of 8 falsy values in Javascript:

  • undefined
  • NaN
  • null
  • false
  • "" (Empty String)
  • 0 (0 is an alias for +0)
  • -0
  • 0n (BigInt)

We can validate whether the above values are falsy or not by passing them as a parameter to the truthyOrFalsy function we defined at the starting of this article.

truthyOrFalsy(undefined); // Falsy Value truthyOrFalsy(NaN); // Falsy Value truthyOrFalsy(null) // Falsy Value truthyOrFalsy(""); // Falsy Value truthyOrFalsy(false) // Falsy Value truthyOrFalsy(0); // Falsy Value truthyOrFalsy(-0); // Falsy Value truthyOrFalsy(0n); // Falsy Value

Truthy Values

Despite we might think that the **empty array( [] ) or empty object( {} )**should be falsy values, but they are actually truthy values in Javascript.

truthyOrFalsy([]); // Truthy Value truthyOrFalsy({}); // Truthy Value //some more truthy values truthyOrFalsy(42); // Truthy Value truthyOrFalsy(new Date()); // Truthy Value truthyOrFalsy(“Welcome”); // Truthy Value

I hope this article helped you learn about truthy and falsy values in javascript. Please share your experience in using these in your codebase which may help everyone get some more clarity of the concept.

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