Key Concepts

Review core concepts you need to learn to master this subject

Function Parameters

Multiple Parameters

Functions

Function Indentation

Calling Functions

Function Arguments

Function Keyword Arguments

Returning Multiple Values

See more

Function Parameters

def write_a_book(character, setting, special_skill):
  print(character + " is in " + 
        setting + " practicing her " + 
        special_skill)

Sometimes functions require input to provide data for their code. This input is defined using parameters.

Parameters are variables that are defined in the function definition. They are assigned the values which were passed as arguments when the function was called, elsewhere in the code.

For example, the function definition defines parameters for a character, a setting, and a skill, which are used as inputs to write the first sentence of a book.

Functions
Lesson 1 of 2
  1. 1
    Functions
    This lesson requires you to know the basics of hamburger-making: * Place the bread down * Add the burger patty * Add the pickles * Place the bread on top What if you had to say each step every tim…
    Start
  2. 2
    Functions for Reusability
    Instead of giving those instructions for every hamburger, we can group and name them as a single function: function makeHamburger() { Add bread Add burger patty Add pickles } A function …
    Start
  3. 3
    Functions for Flexibility
    Not everyone wants to eat hamburgers. We could write a new function for each new sandwich type, but that takes a lot of work and risks making mistakes. Instead, we’ll generalize the hamburger f…
    Start
  4. 4
    Functions for organization
    A sandwich wouldn’t be complete without fries and dessert! Here are the instructions to make the complete meal: * Add bread, Add burger patty, Add fried potatoes, Add pickles, Add bread, Add salt…
    Start
  5. 5
    Putting It All Together
    Time to get coding! It’s okay if you don’t recognize all the symbols in this code: we’ll walk you through the parts you need to know. The makeSandwich() function is provided in main.js. It is …
    Start
  6. 6
    Review
    Well done! Functions are a fundamental concept in programming, and learning the basics will serve you wherever your path leads, regardless of language or domain. To review: * A function is a sequ…
    Start