Key Concepts

Review core concepts you need to learn to master this subject

Control Flow

In programming, control flow is the order in which statements and instructions are executed. Programmers are able to change a program’s control flow using control structures such as conditionals.

Being able to alter a program’s control flow is powerful, as it lets us adapt a running program’s behavior depending on the state of the program. For example, suppose a user is using a banking application and wants to withdraw $500. We certainly want the application to behave differently depending on whether the user has $20 or $1000 in their bank account!

Lesson 1 of 2
  1. 1
    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…
  2. 2
    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 …
  3. 3
    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…
  4. 4
    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…
  5. 5
    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 …
  6. 6
    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…

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