class1-prep

Module 2

Prep for Class 1

Before coming to Class 1, please complete the following tasks:

Lecture:

Task	Resource Type	Link	Instructions
Watch	Lecture	Week 2	Watch this week's first lecture. You can skip from 9:00 to the 19:30 minute mark (David makes Harvard-specific announcements, and talks about their academic honesty guidelines).

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Types, Typecasting, Imprecision

Task	Resource Type	Link	Instructions
Watch	Short	Typecasting	Watch this short, which focuses on data types and typecasting.
Follow-Along	Walkthrough	floats-0	Following David, write a program that prints out a float. Start writing the program first by grabbing the code from the Helpful Resources here.
Follow-Along	Walkthrough	floats-1	Keep following David to solve the problem from the previous video. You can get instructions to start the program here.
Follow-Along	Walkthrough	floats-2	Continue the follow-along with David as he "blows your mind" with floating-points! You can get instructions to start the program here.
Read	Resource	Typecasting	Read over this resource that should help reinforce your knowledge of numeric types, and how/when to cast between them.

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Chars, ASCII

Task	Resource Type	Link	Instructions
Read	Resource	Chars	We've seen int, float, string. Now learn about a new data-type, the char.
Read	Lecture Notes	Week 2 / Typecasting	Read the notes for the "Typecasting" section. This will explain typecasting using a program that converts alphabetical letters to their ASCII equivalents. Stop at the References header.
Follow-Along	Walkthrough	ascii-0	Follow David to write the same ASCII program you just read through in the Lecture Notes. Start writing the program first by grabbing the code from the Helpful Resources here.
Follow-Along	Walkthrough	ascii-1	Continue following David. Pay attention to when David talks about equivalence between chars and ints. You can get instructions to start the program here.

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Functions

Task	Resource Type	Link	Instructions
Read	Resource	Calling Functions	Read over this resource to review how to call a library function, and understanding a return value vs a side effect.
Do	Exercise	Small Talk	Write a program that makes small-talk with the user, responding differently for lengths of inputs
Read	Resource	Creating Functions	This resource explains how, in addition to using other people's functions like printf and strlen, we can also write and use our own functions.
Read	Lecture Notes	Functions and Arguments	Read the "Functions and Arguments" section of the notes, which reviews how to define your own function. Stop at the Problem Set 1 header (don't be confused: these notes are from the previous week, but we find them helpful to include here).
Watch	Doug's Playlist	Functions	Watch Doug's video where he breaks down functions. Feel free to practice with the problems he gives you. You can also check out the Functions section of the C Language cheat sheet here when you've finished the video.
Follow-Along	Walkthrough	functions-0	Follow David to write a program in which you create your own function. Start writing the program first by grabbing the code from the Helpful Resources here.
Follow-Along	Walkthrough	functions-1	Now you'll implement a function that returns a return value. You can get instructions to start the program here.
Read	Resource	Step Into	This video introduces you to the step into feature of the debugger, using the functions-1 example.
Do	Exercise	Census	Get some practice calling a function to make a repetitive program more concise and eloquent. We give you some code and ask you to refactor it by replacing a repetitive code block with a call to a function.
Watch	Shorts	Return Values	You might find this video somewhat confusing, especially at the end where he does an example interacting with a file, which you haven't seen before. But you might also find it somewhat helpful, so we kept it in.

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Scope

Task	Resource Type	Link	Instructions
Read	Lecture Notes	Week 2 / Functions	Read over the notes from the "Functions" section. Although the focus is on creating functions, pay specific attention to the parts that talk about declaring functions, and scope. Stop when you get to the Representing Strings header.
Watch	Doug's Playlist	Variables and Scope	Doug discusses the importance of variables and scope, and how those relate to functions.
Watch	Shorts	Scope	This short will provide some examples that highlight the importance of scope. Also, David mentions "stack frames" and memory towards the end - don't worry about that for now.
Read	Resource	Variable Scope	Here we look at a progam with a bug related to a looping variable and its scope.
Do	Exercise	How Maneee	Here we give you a buggy program that uses scope incorrectly. Try to fix it!

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Strings

Task	Resource Type	Link	Instructions
Read	Lecture Notes	Week 2 / Representing Strings	Read the notes about "Representing Strings". This should be useful for the studio you'll do in Class 1.
Follow-Along	Walkthrough	string-0	Now follow-along as David Malan implements the string program you read through in the notes. Start writing the program first by grabbing the code from the Helpful Resources here.
Follow-Along	Walkthrough	string-1	Keep going, as David talks about the instance where GetString returns NULL. You can get instructions to start the program here.
Follow-Along	Walkthrough	string-2	We can make this program even better by improving its efficiency. Follow David as he shows you how to do that. You can get instructions to start the program here.
Read	Resource	More on For-Loops	A brief digression to clear up any confusion about that fancy for-loop: c for (int i = 0, n = strlen(s); i < n; i++) and introduce other ways to make fancy for-loops
Do	Exercise	String with Indexes	Practice what you've learned about strings and indexes by writing a program that prints each character in a string along with its index.
Follow-Along	Walkthrough	capitalize-0	Follow David to create a program that capitalizes a string given by the user. Start writing the program first by grabbing the code from the Helpful Resources here.
Follow-Along	Walkthrough	capitalize-1	Continue following along as David introduces you to the islower and toupper functions. You can get instructions to start the program here.
Follow-Along	Walkthrough	capitalize-2	Follow as David goes through the "man page" for the toupper function in order to further refine this program. You can get instructions to start the program here.

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The Modulo Operator %:

Task	Resource Type	Link	Instructions
Read	Resource	Modulo	Learn about the modulo operator by looking at a simple example program.
Watch	Doug's Playlist	Operators	Revisit Doug's video about Operators, or just watch the part about modulo if you prefer.
Do	Exercise	Clock Sage	Practice using the modulo operator to write a program that asks for an amount of time in hours, and then calculates what time it will be that many hours in the future.

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Now you're ready for Class 1