CS50's Introduction to Computer Science

Overview

This is CS50x , Harvard University's introduction to the intellectual enterprises of computer science and the art of programming for majors and non-majors alike, with or without prior programming experience. An entry-level course taught by David J. Malan, CS50x teaches students how to think algorithmically and solve problems efficiently. Topics include abstraction, algorithms, data structures, encapsulation, resource management, security, software engineering, and web development. Languages include C, Python, SQL, and JavaScript plus CSS and HTML. Problem sets inspired by real-world domains of biology, cryptography, finance, forensics, and gaming. The on-campus version of CS50x , CS50, is Harvard's largest course.

Students who earn a satisfactory score on 9 problem sets (i.e., programming assignments) and a final project are eligible for a certificate. This is a self-paced course–you may take CS50x on your own schedule.

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HarvardX pursues the science of learning. By registering as an online learner in an HX course, you will also participate in research about learning. Read our research statement to learn more.

Harvard University and HarvardX are committed to maintaining a safe and healthy educational and work environment in which no member of the community is excluded from participation in, denied the benefits of, or subjected to discrimination or harassment in our program. All members of the HarvardX community are expected to abide by Harvard policies on nondiscrimination, including sexual harassment, and the edX Terms of Service. If you have any questions or concerns, please contact [email protected] and/or report your experience through the edX contact form.

Taught by

David J. Malan

Reviews

4.6 rating, based on 138 Class Central reviews

Start your review of CS50's Introduction to Computer Science

Riham Soliman @ReeButterCup

Riham Soliman completed this course, spending 30 hours a week on it and found the course difficulty to be hard.

They were not kidding when they said the course was "demanding". I spent at least 2 hours daily working on the course and each course week took me a month to complete. It was exhausting a lot of the time. The problem sets are designed in such a way that...

They were not kidding when they said the course was "demanding". I spent at least 2 hours daily working on the course and each course week took me a month to complete. It was exhausting a lot of the time. The problem sets are designed in such a way that one is forced to read and do further research to accomplish them. The sense of satisfaction I gained from completing each problem set was tremendous and even though the learning curve is steep (to say the least), I am now comfortable in my understanding of the basics of computer science and in coding in C. The web design module was probably the most fun even though for me personally it was the most demanding.

I guarantee you will be pulling your hair out sometimes if you take this course, but you will have tremendous fun most of the time and the sense of accomplishment is exhilarating!
Anonymous

Anonymous is taking this course right now, spending 5 hours a week on it and found the course difficulty to be hard.

This course is not for beginners. I wanted to learn programming for fun, to understand what my husband does, and learn something new at a leisurely pace. But introduction means nothing, you jump right into problems sets that are extremely challenging....

This course is not for beginners. I wanted to learn programming for fun, to understand what my husband does, and learn something new at a leisurely pace. But introduction means nothing, you jump right into problems sets that are extremely challenging. The instructor speaks at a lightening speed, bouncing around ideas, as if talking fast will keep me interested. It does the exact opposite, I'm like "what is happening?" I also consider myself a studious person and a classroom teacher and this didn't feel basic. For someone who's never written any code and learning for fun, my frustration level was way too high and preventing me from moving on. I needed more scaffolding/building blocks (again this is supposed to be an introduction) because I just wasn't understanding what he was talking about no matter how many times I looked back at the notes, lectures, slides; I couldn't piece it together and had to find another more suitable course for my level.
Erik Trautman

Erik Trautman completed this course and found the course difficulty to be hard.

CS50 turned out to be precisely what I wanted. The platform is reliable, the UX is crisp, and, most importantly, the course content is phenomenal. Professor David Malan and his army of TAs put an absurd amount of effort into giving Intro to Computer Science actual LIFE. From the first video, it inspired that nervous excitement that always accompanied my setting foot into a lecture hall for the first time. This wasn't YouTube, this was the Real Deal.

Because the course was hard. The homework assignments, which were offered via the same appliance that the live students used and submitted to the same grading tool as well, took me anywhere from four to twelve hours apiece.
Rui Ma @ruima

Rui Ma completed this course, spending 2 hours a week on it and found the course difficulty to be easy.

This is CS50x, Harvard University's introduction to the intellectual enterprises of computer science and the art of programming for majors and non-majors alike, with or without prior programming experience. An entry-level course taught by David J. Malan, CS50x teaches students how to think algorithmically and solve problems efficiently. Topics include abstraction, algorithms, data structures, encapsulation, resource management, security, software engineering, and web development. Languages include C, Python, SQL, and JavaScript plus CSS and HTML. Problem sets inspired by real-world domains of biology, cryptography, finance, forensics, and gaming. The on-campus version of CS50x, CS50, is Harvard's largest course.
Anonymous

This course takes you through the proverbial weeds of computer science. We start from an bottom up approach, learning about how computers only understand binary, then how a layer of ASCII makes more intelligent; it's extension with UNICODE, how in modern...

This course takes you through the proverbial weeds of computer science. We start from an bottom up approach, learning about how computers only understand binary, then how a layer of ASCII makes more intelligent; it's extension with UNICODE, how in modern world we arrived at different languages, we get to understand how layer by layer everything is connected and it goes back to binary. After this we learn literally from SCRATCH different programming languages, difference and more importantly similarities between them. All of this in only the first lecture. And there's more to each lecture after this.
Given we only touch the concepts but I think that that's what introduction is supposed to be about and nevertheless if you follow the P-sets and assignments, you are bound to make the time spent on this course more productive than any other time in your life. Do I think this course is hard? - Well, Sure; Are the problem sets difficult? - Definitely; Will it require too much time studying outside of lectures? At this stage I will say, you will spend as much as 10 times the time spent on lectures, to study outside material. I know a lot of you will be discouraged but let me assure you, not only will you be proud of your progress at the end but learning this way will also make you self reliant and ready for future challenges in computing world. There are communities for this course which will help you only if you ask. If you want to follow this course I suggest you give your everything, kitchen sink included. A sincere effort will take you a long way. What matters at the end is where you end up at the end of course compared to yourself at start, and that difference is unfathomable.
Credit where credit is due; It takes great effort and commitment to come up with quality course like this and David Malan, being the great teacher that he is, does it year after year, semester after semester, and makes it look ridiculously easy (I guess that's how Legends like to do it.) The whole team of CS50 and CS50X has put unbelievable amount of effort in this course and it can be seen in every small detail in the course. Hats off to them.
Mark Mahoney

Mark Mahoney completed this course, spending 20 hours a week on it and found the course difficulty to be hard.

CS50x is essentially like taking a real, full-length college-level course, complete with lectures, breakout sections, walkthroughs, homework, quizzes, etc...

Prepare to be infuriated after watching 5-6 hours of video content and realizing that you still have absolutely no idea how to actually do the homework. If you're looking for somebody to hold your hand through the syntax (like the 56% of people with no background in CS likely were), you won't find it here.
David Venturi

David Venturi completed this course, spending 20 hours a week on it and found the course difficulty to be hard.

(Full review: https://medium.com/@venturidb/review-harvard-cs50-introduction-to-computer-science-75405e684a61#.1jq3325cw)

I’m having a hard time describing CS50 without sounding hyperbolic. The course was just so damn good. The content is engaging. David Malan is too good at his job. The production value is absurd. Honestly, go check out a lecture for the production value alone.

I have now completed CS50, Stanford CS101, and half of Udacity CS101 and without question Harvard’s introduction to computer science is my favourite.
Ephrem Tesfaye

I am a resident of china. My father is a daily wage labourer and mother is a housewife. Our annual income is pretty low wrt to the average nation’s income. I think it will be beneficial for me to get into the firm as an intern. But I’ve no job of my own...

I am a resident of china. My father is a daily wage labourer and mother is a housewife. Our annual income is pretty low wrt to the average nation’s income. I think it will be beneficial for me to get into the firm as an intern. But I’ve no job of my own to carry the expanses to pay for the certificate of this course. I live only for my scholarship. In this circumstance, it is very much difficult for me to gather such amount of money for the certificate. Financial Aid will help me take this course without any adverse impact on my monthly essential needs. So I’m badly in need of this financial aid. Receiving this Financial Aid will open for me a new horizon of the world of Coursera courses, which in turn will help me in future. I also plan to complete all assignments on or before time as I have done in previous Signature Track Courses. Also, I intend to participate in Discussion Forums, which I have found to supplement my learning immensely in the other online courses I have taken on Coursera. I also plan to grade assignments, which are to peer-reviewed, which I believe will an invaluable learning opportunity
Anonymous

Anonymous is taking this course right now.

The lectures are phenomenal but it stops there. David only touches on topics during his lectures. Then you are asked to complete problem sets when no one ever taught you any of the skills necessary to complete them. And by "no one ever taught you" - I mean no one even brought up the subject in the lecture. You must look up and teach yourself 90% of what you need to do the problem sets. If I wanted to teach myself the majority of the information I need, I would not have enrolled in a class. Two stars for the lectures. Zero stars for everything else.
Anonymous

How to take the course smartly: •Watch the shorts first THEN the lectures to have more time internalizing the concepts. •There are more (old) short videos & notes on obscure playlists at youtube and their old site (available with wayback machine) which...

How to take the course smartly:

•Watch the shorts first THEN the lectures to have more time internalizing the concepts.

•There are more (old) short videos & notes on obscure playlists at youtube and their old site (available with wayback machine) which have more complete & necessary information.

•Search for various walkthroughs to every problem set, also you'll find on discord a separate room chat for all of them.

•Understand the problems on paper first, have pseudocode (at least in your head) then start to try to code. It makes it a little boring, but trial & error blindly takes a lot of unnecessarily wasted time.

•Don't cheat: so for example looking up an algorithm, or an explaining article on the topic is not cheating but copying or modeling any kind of explicit code example into your own code is.

+1

If you're a complete beginner, type the examples out with David during the lecture. It really is not the same as just watching and thinking you know it. They're well designed little programs.
Anonymous

Anonymous completed this course.

This is course was one of the best things I ever found ever since I started programming!
The course is, yes , not being difficult is definitely on the harder side. The lectures are of great quality, are to the point, and the instructor too is great! The problem sets were pretty good too. Also if your are in a dilemma that this might too hard for you, take it. Believe me, if you are sincere and dedicated enough, you will do it. Please note that I did know python before taking this course , but even if you don't know anything about programming, you will do just fine! Highly recommended for beginners.
Anonymous

Anonymous completed this course.

I am currently taking MIT's python course. It is designed much better for beginners. While lectures for CS50 are phenomenal, problem sets are not realistic and quite discouraging. I am glad I decided to try something else.
Anonymous

I started the course two years ago. It was so dificult and demanded so many extra searchs that I found better to learn with books. Now I just returned to get the certificate. The idea is nice but you can find better matterials and better support for free on the internet. In the end have the certification with the name Harvard is a good thing.
Kidanemariam Abebe

This course is not for beginners. I wanted to learn programming for fun, to understand what my husband does, and learn something new at a leisurely pace. But introduction means nothing, you jump right into problems sets that are extremely challenging
Abhigyan Das

CS50 is a phenomenal experience. I say experience because it is more than a MOOC. The course team and especially the lead instructor for the course Professor David J. Malan has demonstrated exceptional vision and aptitude in implementation when designing...

CS50 is a phenomenal experience. I say experience because it is more than a MOOC. The course team and especially the lead instructor for the course Professor David J. Malan has demonstrated exceptional vision and aptitude in implementation when designing this course. Far from being a just a series of lectures, CS50 sets you up for success. A big part of this is the helpful and inclusive community. CS50 actively fosters community engagement by organising events and seminars. Apart from this the lectures themselves are of excellent quality and present the material in a manner that is both approachable yet engagingly challenging. Every lecture is followed by problem sets which not only consolidate your grasp of the material but make the course more engaging. CS50 also provides free access to cloud based development environments which you can use to store your assignments and host your course projects. Overall CS50 is one of the best MOOC experiences I've ever had. My only complaint with the course is style50 - CS50's scrupulously dogmatic enforcer of pedantic code style guidelines :'(
Robert Grutza

Robert Grutza completed this course and found the course difficulty to be medium.

There is a lot of good stuff here, but is is so painfully disorganized it is a chore to figure out. Navigating the dozen sites associated with the class is more difficult than the actual material. If they ever organized this, it could be good. It is like they are trying to waste as much student time as possible for very basic instruction.
Kirubel Getnet

it's good course and this is a big responsiplity thanks for give this chance for me and please add the cyber securityh or ethical hacking course with free thanks forr all
Anonymous

CS50 is fantastic. I read that it is the single most popular course at Harvard. People who aren’t even CS majors sign up to take the course. On campus, they have tshirts, free food, a hackathon, etc. You don’t get any of that on edX, but you do get the...

CS50 is fantastic. I read that it is the single most popular course at Harvard. People who aren’t even CS majors sign up to take the course. On campus, they have tshirts, free food, a hackathon, etc. You don’t get any of that on edX, but you do get the following: a great IDE developed by CS50 TAs, a community of support on reddit, stackoverflow, facebook, twitter, etc., debugging tool (debug50), and a tool to immediately check if your pset solution is correct (check50). There is even a little fun CS50 tv show with little 2 min episodes after each lecture. I could go on. You don’t have to take notes on the lectures because there’s a webpage that has all the notes. There are short videos done by TAs explaining some of the concepts in more detail. There are walkthroughs that help you set up the pset solutions.
Peter

Peter completed this course, spending 10 hours a week on it and found the course difficulty to be hard.

Excellent course. David Malan explains everything very well and is very interactive, using his students to help explain different concepts.

I especially enjoyed the data structures and algorithms part of the class.
Anonymous

This is CS50x , Harvard University's introduction to the intellectual enterprises of computer science and the art of programming for majors and non-majors alike, with or without prior programming experience. An entry-level course taught by David J. Malan, CS50x teaches students how to think algorithmically and solve problems efficiently. Topics include abstraction, algorithms, data structures, encapsulation, resource management, security, software engineering, and web development. Languages include C, Python, SQL, and JavaScript plus CSS and HTML. Problem sets inspired by real-world domains of biology, cryptography, finance, forensics, and gaming.