Question

While reading Eloquent Javascript (Chapter 6) I am trying to grasp fundamental concepts. There is discussion about Higher-Order functions in Javascript. Is the function processNumbers() in the following code a Higher-Order function?

function addNumbers(number1, number2) {
  return (number1 + number2);   
}

function processNumbers(action, number1, number2) {
  return action(number1, number2);
}

document.write(processNumbers(addNumbers, 2, 10));​​​​​​​​

Answer 1

From Wikipedia:

In mathematics and computer science, a higher-order function (also functional form, functional or functor) is a function that does at least one of the following:

• take one or more functions as an input
• output a function

So yes, processNumbers is a higher-level function as it takes in a function as input via the action parameter.