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Ivan Karbashevskyi
Ivan Karbashevskyi

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Making JavaScript Fun with is.false and is.not_false from 'thiis'

JavaScript is an adventure! It's like a treasure hunt where you're looking for the right data types. One of the gems you might come across is the boolean value false. But what if you want to be sure that a value is really false or that it's anything but false? That's where the is.false and is.not_false methods from the 'thiis' package come to the rescue. In this article, we'll explore these fantastic tools that make type checking in JavaScript more playful and precise.

The Treasure of false in JavaScript

Before we embark on our journey, let's have a quick chat about what booleans are in JavaScript. Booleans are like the 'yes' and 'no' of the programming world. They have only two values: true and false. You'll often find them in decision-making and conditional statements.

Meet is.false - The Boolean Detective

Documentation link

Imagine you're on a quest to find the elusive false value in your code. That's when the is.false method comes to your aid. It's like a trusty detective who ensures that a value is specifically false. Let's see how it works:

import { is } from 'thiis'; // Import the "is" object from the "thiis" package

const myValue = false;
const result = is.false(myValue);

console.log(result); // true
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In this example, we import the "is" object from the "thiis" package and use the is.false method to confirm that myValue is indeed false. As expected, it returns true because the value is indeed false.

The Playful Scenarios

Now, let's dive into some fun and practical scenarios that showcase how you can use is.false and its playful partner, is.not_false.

1. Chasing Bugs Away with is.false

When debugging your code, you often encounter unexpected values. You can use is.false to hunt down the elusive bugs and ensure they're really false:

import { is } from 'thiis';

const mysteriousValue = someFunctionThatMayReturnFalse();

if (is.false(mysteriousValue)) {
  // Bye-bye, pesky bugs!
} else {
  // Continue your quest with confidence.
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2. The is.not_false Hero

Now, let's introduce the hero of the day - is.not_false. This method is like your guardian angel, ensuring a value isn't false. It's particularly handy when you want to be certain that a value isn't leading you astray:

import { is } from 'thiis';

const importantValue = someFunctionThatMayReturnAnythingButFalse();

if (is.not_false(importantValue)) {
  // Your guardian angel saved the day!
} else {
  // Time to handle other possibilities.
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3. Creative Validation with is.false

Let's say you want to validate a user's response. You can use is.false to make sure they're not fibbing and have given a genuine false response:

import { is } from 'thiis';

function validateUserResponse(response) {
  if (is.false(response)) {
    return 'Thanks for your honesty!';
  } else {
    return 'Hmm, interesting...tell me more!';
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4. Making Decisions with is.not_false

In decision-making situations, you might want to ensure that a value isn't false before proceeding. is.not_false helps you make choices with confidence:

import { is } from 'thiis';

const userChoice = getUserInput();

if (is.not_false(userChoice)) {
  // Time to execute the chosen action!
} else {
  // Handle any indecisiveness with grace.
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Of course! Let's add two more fun examples involving is.false and is.not_false for streams and arrays:

5. Stream Stories with is.not_false

If you're into streams and libraries like RxJS, is.not_false is your trusty companion. It ensures that the stream only processes values that are anything but false. Let's set sail on a stream adventure:

import { is } from 'thiis';
import { from } from 'rxjs';
import { filter } from 'rxjs/operators';

const stream$ = from([false, 'not a false value', true, 'really not false', false, 0]);

  .subscribe(value => {
    console.log(value); // Only the truth and non-false values will join the party!
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In this scenario, we create an observable stream (stream$) that emits various values. The filter(is.not_false) operator ensures that only values that are not false are invited to the party, and the subscribe function logs their adventures.

6. Array Adventures with is.false

Just like streams, is.false can accompany you on your array-checking adventures. Use every() to ensure that all elements are indeed false, and some() to check if at least one is:

import { is } from 'thiis';

const falseArray = [false, false, false];
const mixedArray = [true, 'not a false', false, true];

const areAllFalse = falseArray.every(is.false); // true
const hasNonFalse = mixedArray.some(is.not_false); // true

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In the example above, we have two arrays. areAllFalse checks if all elements in falseArray are false, which they are. hasNonFalse checks if at least one element in mixedArray is not false, which is also true.

The Journey Continues

The is.false and is.not_false methods from the 'thiis' package are your trusty companions on your JavaScript adventure. They make type checking playful and precise, ensuring your code interacts with false values exactly as you intend. By adding the 'thiis' package to your JavaScript toolkit and exploring its documentation for more tips and examples, you can navigate the JavaScript landscape with confidence and a dash of fun.

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Ivan Karbashevskyi

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