Exploring Logical Complement in JavaScript

Introduction

In this lab, we will be exploring the concept of logical complement in JavaScript. We will learn how to use the complement function to generate a new function that returns the opposite of the original function. This lab will help us better understand the logic and functional programming concepts in JavaScript.

Skills Graph

Logical Complement

To begin practicing coding, open the Terminal/SSH and type node.

To get the logical complement of a function fn, use the complement function. This function returns another function that applies the logical not (!) operator on the result of calling fn with any arguments supplied.

Here's an example code snippet:

const complement =
  (fn) =>
  (...args) =>
    !fn(...args);

To use this function, define a predicate function, for instance, isEven that returns true if a given number is even. You can then get the logical complement of this function using the complement function, as shown below:

const isEven = (num) => num % 2 === 0;
const isOdd = complement(isEven);
isOdd(2); // false
isOdd(3); // true

Summary

Congratulations! You have completed the Logical Complement lab. You can practice more labs in LabEx to improve your skills.