TS7044

Parameter 'a' implicitly has an 'any' type, but a better type may be inferred from usage.

Broken Code ❌

const multiply = (a, b) => a * b;

Fixed Code ✔️

From the body of the arrow function expression, TypeScript can see by the * that a and b may be of type number:

const multiply = (a: number, b: number) => a * b;