Arrow Functions

The same pricing rule takes three lines as a regular function and one line as an arrow function, and for a small rule the two behave the same.

function doublePrice(price: number): number {
    return price * 2;
}

const doublePriceArrow = (price: number): number => price * 2;

console.log(doublePrice(5));      // Output: 10
console.log(doublePriceArrow(5)); // Output: 10

Arrow functions came to JavaScript with ES6, and TypeScript supports them fully