Higher-Order Functions

The term higher-order functions refers to functions that either take functions as arguments or return functions. The functions we used to create closures in the previous chapter are thus higher-order functions. Higher-order functions are frequently used in R instead of looping control structures, and we will cover how you can do this in general in the next chapter. I will just give you a quick example here before moving on to more interesting things we can do with functions working on functions.