TypeScript Function Types

Functions are core of every app. TypeScript makes them safe. ## Basic typing ```ts function add(a: number, b: number): number { return a + b; } ``` ## Optional params ```ts function greet(name: string, age?: number) { console.log(name, age); } ``` ## Default params ```ts function greet(name: string = "Guest") { console.log(name); } ``` ## Function type variable ```ts let calc: (a: number, b: number) => number; calc = (x, y) => x + y; ``` ## Remember - Always type parameters and returns - Makes APIs predictable