Falsy in JavaScript?

A falsy value is a value that JavaScript treats as false.

Example:

let username = "";

if (username) {
console.log("Username entered");
} else {
console.log("Username is empty");
}

Output:

Username is empty.

(Because an empty string "" is falsy.)

Common Falsy Value:

false
0
-0
0n
""
null
undefined
NaN