Functions are not only the ideal tools for making your program modular, but they also reflect mathematical thinking. You learned the syntax of function definitions and to distinguish between defining and calling a function.

We considered functions as objects that can be modified by other functions. When working with functions, it is important to be familiar with the notion of the scope of a variable and how information is passed into a function by parameters.

Sometimes, it is convenient to define functions on the fly with so-called anonymous functions. For this, we introduced the keyword lambda.