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Ivan Karbashevskyi
Ivan Karbashevskyi

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Mastering Booleans with is.true and is.not_true in JavaScript: Your Guide to True Values

JavaScript is like a grand adventure filled with hidden treasures, and one of the most sought-after gems is the boolean value true. This value is at the heart of decision-making in your code. But how can you be sure that a value is truly true, or conversely, make sure it's anything but true? That's where the is.true and is.not_true methods from the 'thiis' package come into play. In this article, we'll take you on a journey to explore these powerful tools and their potential in JavaScript.

The Magic of true in JavaScript

Before we embark on our adventure, let's understand what true is in JavaScript. It's like a magic wand, representing the "true" or "yes" in decision-making. Recognizing it is crucial for precise and confident programming.

Meet is.true - Your Truth Detector

Documentation link

Imagine you're on a quest to uncover the truth in your code. The is.true method acts as your trusty truth detector, ensuring that a value is indeed true. Let's see it in action:

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

const myValue = true;
const result = is.true(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.true method to confirm that myValue is indeed true. As expected, it returns true because the value is indeed true.

The Journey of Examples

Now, let's embark on an adventure and explore six practical scenarios that demonstrate the versatility of is.true and its companion, is.not_true. We'll cover a range of use cases, including some exciting ones.

1. Discovering True Values with is.true

The primary role of is.true is to identify true values. It helps you determine when a value is indeed true, which can be useful for celebrating success:

import { is } from 'thiis';

const success = someFunctionThatMayReturnTrue();

if (is.true(success)) {
  // Celebrate the triumph!
} else {
  // Keep working towards victory.
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2. Guarding Against true with is.not_true

On the flip side, is.not_true serves as your guardian against true. It's handy when you want to ensure that a value isn't true before proceeding:

import { is } from 'thiis';

const importantValue = someFunctionThatShouldNotBeTrue();

if (is.not_true(importantValue)) {
  // Your guardian prevents "true" mishaps!
} else {
  // Time to explore other possibilities.
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3. User Validation with is.true

When dealing with user input, you may want to validate if the input is indeed true. Use is.true to make sure users are giving you the "true" story:

import { is } from 'thiis';

function validateUserInput(input) {
  if (is.true(input)) {
    return 'You've made a true choice!';
  } else {
    return 'Interesting, tell me more!';
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4. Making Confident Decisions with is.not_true

In decision-making scenarios, you might want to ensure that a value is not true before executing specific actions. is.not_true helps you make choices with confidence:

import { is } from 'thiis';

const userChoice = getUserInput();

if (is.not_true(userChoice)) {
  // Execute actions for valid choices.
} else {
  // Handle scenarios involving 'true' with grace.
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5. Stream of Truth with is.true

Now, let's dive into a scenario involving stream$ from RxJS. Using filter and is.true, we can ensure that the stream processes only true values:

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

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

  .subscribe(value => {
    console.log(value); // Only "true" values will be part of the stream's story.
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In this example, the filter(is.true) ensures that only true values get processed by the stream.

6. Array Exploration with is.not_true

Arrays are another exciting playground for is.not_true. You can use every() to confirm that all elements are not true and some() to check if at least one isn't:

import { is } from 'thiis';

const notTrueArray = [false, 'not true', 0];
const mixedArray = [null, 'not true', true, undefined];

const allElementsNotTrue = notTrueArray.every(is.not_true); // true
const someElementsNotTrue = mixedArray.some(is.not_true); // true

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In this scenario, allElementsNotTrue checks if all elements in notTrueArray are not true, and someElementsNotTrue checks if at least one element in mixedArray is not true.

The Adventure Continues

The is.true and is.not_true methods from the 'thiis' package are your reliable companions on your JavaScript adventure. They make type checking precise and fun, ensuring your code interacts with true values exactly as intended. 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 touch of excitement.

So, keep coding, and remember that the world of JavaScript is full of exciting discoveries!

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Ivan Karbashevskyi

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