If you write JavaScript, you have probably used higher-order functions and not even noticed. If you have ever replaced a for loop with an array method, you’ve used higher-order functions.

Learn what the "this" keyword does in JavaScript in 100 seconds. And stay tuned for a few minutes of more advanced discussion after the credits.

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 ...