Safe Length

Reading a property on null or undefined throws an error at runtime. Use optional chaining (?.) to read safely and nullish coalescing (??) to choose a default.

const s: string | undefined = "hi";
const n = s?.length ?? 0; // 2

Return a number so it’s easy to check in tests and code.

Your Task

Compute a string's length, treating missing as 0.

Write function safeLength(s: string | null | undefined): number.
If s is a string, return its .length.
If s is null or undefined, return 0.
Do not throw or use non-null assertions.