Course placement

Handout written by Keith Schwarz.

The CS department offers many programming courses and it can be difficult to know exactly where to begin. This handout provides a general overview of these classes and some advice about selecting the class that's right for you.

If you have any questions, please feel free to come talk to the course staff! We'd be happy to offer one-on-one advice.

CS106A: Start here!

CS106A is our first-quarter programming course. If you're interested in learning how to program a computer, this is the place to start. CS106A has no prerequisites – it's open to everyone! Most students interested in learning computer programming will start here, including many eventual CS majors.

CS106A focuses on fundamental concepts in computer programming (expressions, conditionals, loops, methods, arrays, etc.) that arise in many different programming languages. Although CS106A is taught in Python, it is not designed as a class in standard Python programming.

In our experience, we've found that some high school CS classes are more rigorous than others. If you do have high school CS experience, we recommend reviewing the syllabus for CS106A to get a sense of what it covers. If you feel that you've seen all these topics before, you may want to start off in CS106B or CS106X. If you’ve covered some, but not all, of the topics from CS106A, you might want to look into CS106AX as a starting point. As always, feel free to ask the course staff if you have questions about where to begin!

We recommend that you take CS106A if

  • You are interested in learning to program computers.
  • You have little to no prior programming experience.

We recommend that you not take CS106A if

  • You have prior programming experience at a level comparable to an introductory college course (for example, if you scored a 4 or 5 on the AP CS exam).
  • You meet the criteria for taking CS106AX and are interested in a more accelerated treatment of the material.
  • You have prior programming experience and want to learn how to program in Python.

Visit the CS106A website.

CS106B: Next step

CS106B is our second course in computer programming. It focuses on techniques for solving more complex problems than those covered in CS106A and for analyzing program efficiency. Specifically, it explores fundamental data types and data structures, recursive problem solving, graph algorithms, and basic algorithmic analysis.

CS106B assumes you have programming experience at the level of CS106A, though you don't necessarily have to have taken CS106A in order to take CS106B. If you've seen basic control structures (conditions, loops), variables, arrays/lists, maps, and program decomposition, then you should be ready to take CS106B.

CS106B is taught using the C++ programming language, but uses C++ more as a vehicle for ideas than as an object of study. If you're interested in studying C++ in depth, consider looking into CS106L.

We recommend that you take CS106B if

  • You have prior programming experience at the level of CS106A.
  • You are interested in learning more about problem-solving with computers.
  • You've programmed before but have not seen recursion, data structures, or algorithmic analysis.

We recommend that you not take CS106B if

  • You already have completed equivalent coursework elsewhere.
  • You have little to no prior programming experience.
  • You have prior programming experience and want to specifically learn C++ programming.

CS107: How it all works

After completing the intro programming sequence, CS107 takes you under the hood to learn the ins and outs of computer systems. It explores how high-level programming constructs are represented internally inside the computer and how those internal representations affect program behavior and performance. Along the way, it provides programming maturity and exposure to developing software in a Unix environment.

CS107 has either CS106B or CS106X as prerequisites and assumes an understanding of fundamental programming techniques and good programming style. As a result, it's rare for incoming students to jump directly into CS107 and to skip the CS106 series entirely. Typically, we'd only recommend this to students with a background comparable to CS106A/B and who already have good programming style. Most students, even those who go on to be CS majors, usually begin in CS106A/B/X.

We recommend that you take CS107 if

  • You have completed CS106B or CS106X or have the equivalent programming background, including familiarity with recursion and fundamental data structures (binary trees, dynamic arrays, linked lists, graphs, etc.)
  • You have experience writing readable code – writing comments, decomposing problems into smaller pieces, etc.

We recommend that you not take CS107 if

  • You have never before taken a class in computer programming.
  • You have prior programming experience but have not met the postconditions of CS106B/X.

Visit the CS107 website.

CS107E: How it works, embedded

CS107E is version of CS107 that covers similar topics but which focuses on programming a small computer that can easily fit into the palm of your hand. The class is smaller and more project-oriented than CS107 and lets you play around with small embedded devices to see how low-level systems concepts directly let you control physical devices. The CS107E FAQ offers perspective on advice on choosing between 107 and 107E.

We recommend that you take CS107E if

  • You meet all the requirements for CS107.
  • You enjoy working on open-ended projects.

We recommend that you not take CS107E if

  • You're nervous about taking CS107 and want to satisfy that requirement in a different way.

Visit the CS107E website.