CS142 Course Information


Lectures are Mondays, Wednesdays, and Fridays from 10:00-11:00AM via the course's Canvas Zoom page. Lecture will be recorded and access via the "Cloud Recordings" on Canvas Zoom. Lecture notes are available in advance and provide an outline for much of the material that will be presented in class.

Additional Materials

There is no required textbook for this class, and I am not aware of a book that is a perfect match to the lecture material. The content of the course is defined by the lectures. You will need additional reference material to complete the programming projects, but this material is available on the Web. One good online source for reference documentation on HTML, CSS, and the DOM is Mozilla Developer Network. A comprehensive book is Dynamic HTML: The Definitive Reference, Third Edition, by Danny Goodman (O'Reilly Media), but this describes the Web as of a few years ago, so it doesn't include newer features such as HTML5. It is freely available to Stanford students via Safari Books Online.

The web application we build in the course's projects will use what is known as the MERN stack. The MERN stack uses the JavaScript language in both the browser and the server-side. The lectures will provide an introduction to JavaScript, but more complete information can be found on the web and in some books freely available to Stanford students through Safari Books Online.

The class project assignments, lectures and sections will cover what you need to know about the MERN stack. For additional material recommend starting at the web sites of the different components:


The official prerequisites for this class on ExploreCourses are CS107 and CS108. These are listed as the prerequisites because we expect a certain level of engineering maturity and experience. You should be comfortable working with the command line, picking up a new language and framework, reading technical documentation, and debugging your code. Students who have taken this class directly after 106B/X have had to work harder and spend more time than their peers, but it's not impossible. If you have any questions about whether you should take this class, please feel free to contact the staff.

Discussion Sections

The class will have weekly discussion sections led by the course assistants. The sections will supplement lecture content with additional examples as well as cover material needed for the projects. Attendance is not mandatory but we highly encourage you to attend. Like the lectures, the discussion sections will be available via Cloud Recording.


The class will include 8 projects, one due each week except the first and middle week of the quarter. Projects will be due at the same time each week, on Thursdays at 11:59 PM except for Project #7.

We encourage you to discuss the projects with other students; both giving and receiving advice will help you to learn. It's fine to discuss overall strategy, share tips about Web technologies (useful CSS styles, library methods, etc.), and give and receive debugging assistance. However, you must write your own code. It's not OK to share code or write code collaboratively. The projects are intended to be simple enough for each person to implement all of every project.

The last three projects build upon the previous project ending with a working photo sharing website. Because of these dependencies between the projects, completing the later projects requires doing the ones that precede it. The course staff will not provide solutions to projects but we can work with students after a project's deadline to get the student's code working well enough to do the next assignment.

Please do not post your project solutions on the Web, either during or after the class. Students occasionally do this because they are proud of their class work (some of the work in this class is quite good!), but this makes it easy for future students to copy your work rather than figuring things out for themselves. Posting solutions on the Web is a Stanford Honor Code violation, since it it has the effect of giving improper assistance to other students.

Style points: most of the grade for each project is based on the functionality of your project (does it do what the problem asks?). However, for each project there are also a few extra style points, which are awarded based on the way you solve the problem, not how your solution behaves. These reflect the importance of things such as proper HTML validation, clean code structure, and nice-looking interfaces. The style points to be awarded for each project are described near the end of each project description.

Late Days

Each student is allowed a total of 3 late days, which may be spent in units of one day (24 hours) on any projects throughout the quarter. Late days are intended to cover special situations such as illness and family emergencies, so use them wisely. Once your late days have been used up, a penalty of 25% of the project's total score will be assessed for each day a project is late. Projects more than four days late will not receive any credit. Due to the dependencies between projects, students may need to complete projects even if they did not receive credit for it. See the discussion on project dependencies above.

Note that the course projects are not weighed the same, and the latter projects will be worth more points than the earlier ones. Since the "free" late days cannot be moved around between projects, please strongly consider saving them for the latter projects so less/no penalties are applied towards the latter projects, which will be more costly.


Unfortunately, Web browsers are still not 100% identical in their behavior, so Web pages may behave differently on different browsers. For this class, the reference browser is Chrome: your project solutions must work on Chrome, and the CAs will use Chrome to test them. Your solutions need not work on any browser other than Chrome. You may use a different browser to develop your solutions if you wish (Chrome, Firefox, and Safari all have very similar behavior), but please test on Chrome before submitting. We do not recommend that you use Internet Explorer for development: historically, its behavior has been quite different from the other browsers, so things that work on IE may not work on Chrome, and vice versa.


The class will have 3 timed quizzes that cover material presented in lectures but not emphazied by the programing projects. The quizzes will be 45 minutes long and must be complete during the following time periods:

Quiz # Available Due By
1 Mon, Apr 19, 11:30AM PDT Tue, Apr 20, 11:30AM PDT
2 Mon, May 10, 11:30AM PDT Tue, May 11, 11:30AM PDT
3 Wed, Jun 02, 11:30AM PDT Thu, Jun 03, 11:30AM PDT


We sometimes make mistakes in grading, both on projects and quizzes, and are happy to correct these if you point out the error. To request a regrade, add a comment on your graded submission or quiz on Canvas with the first word of the comment being "REGRADE". The comment box is located on the grade detail view accessed by clicking on the project or quiz in the Grades view on Canvas. Regrade requests must be submitted within 5 days after we send out the grades for a project or quiz.

Regrade requests should focus on errors (i.e., something we thought was wrong but actually was right, or you believe we misunderstood your work). There may be situations where you agree you made an error but disagree about the number of points deducted; unfortunately, we cannot change your score in these situations, because it would require a change in the grading rubric and thus require us to regrade all of the projects or quizes.

Grading Policy

Grades for the class will be determined as follows:

  • Projects: 70%
  • Quizzes: 30%

Students with Documented Disabilities

Students who may need an academic accommodation based on the impact of a disability must initiate the request with the Student Disability Resource Center (SDRC) located within the Office of Accessible Education (OAE). SDRC staff will evaluate the request with required documentation, recommend reasonable accommodations, and prepare an Accommodation Letter for faculty dated in the current quarter in which the request is being made. Students should contact the SDRC as soon as possible since timely notice is needed to coordinate accommodations. The OAE is located at 563 Salvatierra Walk (phone: 723-1066).