What distinguishes between the methods of detecting falsy and truthy values?

While working with JavaScript / Typescript, I often find myself needing to verify if a length exists or if a value is true or false.

So, the main query arises: are there any differences in performance or behavior when checking like this...

const data = ['hello', 'good', 'day'];
(data.length) //  yields true 
(data.length > 0) // also results in true

similarly

const booleanValue = false;
(!booleanValue) // returns true 
(booleanValue === false)  //also gives true

Is there an optimal approach for these checks or does it all come down to readability?

Answer №1

When aiming for different outcomes, there are variations in the results...

For instance:

0 == false // true
0 === false // false
undefined == null // true
undefined === null // false
...

Explore this interactive game to grasp the concept of Boolean relationships in JavaScript: Interactive Learning Game

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