React & Modern Frontend (445 Qs)•Part 7: Supported Libraries, Styling & Integrations (139 - 151)
What is Flow?
Flow is a static type checker designed to find type errors in JavaScript. Flow types can express much more fine-grained distinctions than traditional type systems. For example, Flow helps you catch errors involving null, unlike most type systems.
Practical Code Example
javascript
// Flow: Static type checker for JavaScript developed by Facebook
// @flow
function square(n: number): number {
return n * n;
}