'falsy' values in JavaScript

'falsy' values in JavaScript

All values when passed to Boolean() returns false are 'falsy' values.

The below are the finite set which is considered as 'falsy' values in JavaScript. All others are considered as 'truthy'. It's like vowels and consonants in English alphabets.  

'' or `` or ""
0n //BigInt

It's very easy to filter the above 'falsy' values in a variable,

let a = false;
if (a) {
	//does not enter


if (Boolean(a)) {
	//does not enter

But one has to be careful when dealing with 0, false, or null as users may genuinely what to input those values to your API or DB etc.  

The below method ignores 0, false, and null but only check for empty strings, undefined, NaN and empty object values. If you find it useful, please feel free to use it.

You can replace typeof value === 'string' and isNaN(value) with more reliable checking. Links below.

Reliable way to check datatypes in JavaScript
Many versions have come & gone, but this one liner is always a winner 🏆!
NaN? isNaN? Who’s NaN👵? Checkin’ out JavaScript NaNs the right way.
Hint💡: Please don’t use isNaN()
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