Hands-On Design Patterns with React Native

Higher-order functions

We have learned about higher-order components, and in this section, we will have a look at the more general concept, called higher-order functions.

Have a look at the example. It's pretty straightforward. You wouldn't even notice you created anything special:

const add5 = x => x + 5; // functionconst applyTwice = (f, x) => f(f(x)); // higher order function


applyTwice(add5, 7); // 17

So what is a higher-order function?

A higher-order function is a function that does one of the following:

• Takes one or more functions as an argument
• Returns a function

That's it; it's so simple.