Nullability - JS
function print(s) {
console.log(s);
console.log(s.length);
}
// incorrect usage, valid
print(); // `undefined`, Uncaught TypeError: s is undefined
print(undefined); // `undefined`, Uncaught TypeError: s is undefined
print(null); // `null`, Uncaught TypeError: s is null
// correct usage, valid
print("hello"); // hello, 5