‘Higher-order functions’ is a fancy term for functions that take other functions as arguments or that return functions. Very powerful!

Let's look at each of these in more detail. Functions are first-class citizens In functional programming, functions are treated as first-class citizens. Functional programming supports higher-order ...

Unfortunately, this function immediately “forgets” the second value and never does anything with it. Our inner function, the one that currently just returns value1, also needs to be modified ...