[JS] Falsy Values

About

A falsy (or falsey) value is a value that's considred false when encountered in a Boolean context.

Falsy Values in JavaScript

Value	Description
false	The keyword false.
0	The Number zero (so, also 0.0, etc., and 0x0).
-0	The Number negative zero (so, also -0.0, etc., and -0x0).
0n	The BigInt zero (so, also 0x0n). Noe that there is no BigInt negative zero -- the negation of 0n is 0n.
"", '', ``	Empty string value.
null	null -- the absence of any value.
undefined	undefined -- the primitive value.
NaN	NaN -- not a number.
document.all	Objects are falsy if and only if they have the [[IsHTMLDDA]] internal slot. That slot only exists in document.all and cannot be set using JavaScript.

REF

• MDN Web Docs - Falsy