Week 0

This is CS50.

• David tells his own story of shopping CS50 long ago during his sophomore fall and taking it pass/fail, only find out how empowering the field of Computer Science was and how it intersects with the humanities, arts, and other sciences.

• 73% of CS50 students have never taken a CS course before, so rest assured that you are not alone, especially if you have no prior experience in CS.

• "what ultimately matters in this course is not so much where you end up relative to your classmates but where you, in Week 11, end up relative to yourself in Week 0"

• At the end of the day, computer science is about problem solving: taking some inputs (the problem we might be trying to solve) and creating some outputs (perhaps a solution to the problem).

• Between those inputs and outputs is what we might call a "black box," something that solves the problem for us even if we might not know or care how it solves them.

• The inputs and outputs for a computer, for example, are just electricity (from a plug or battery) and changes on its screen.

• But let’s think about how we might represent information. If David wanted to count the number of students, he might use his fingers (and quickly run out), or use tally marks:
  

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• Some of these lines are actions we might take, like pick up or open to or look at or call. We’ll call these functions.
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