5
votes
Accepted
Week 1 compiling String.c using clang instead of make
The make utility actually calls the clang compiler with special options that can be set for a project.
When I run make in the ide it actually runs the following:
clang -fsanitize=integer -fsanitize=...
- 814
4
votes
Accepted
What is the difference between ++i and i++?
x++ - Post-increment operator
++x - Pre-increment operator
In short,
x++ - x is incremented after the current statement is evaluated.
++x - x is incremented before the current statement is evaluated.
...
- 379
4
votes
Accepted
Why do I not have to link stdio.h while compiling with clang?
stdio.h is a header file from the C Standard Libraries, and their implementations are in the libc.a file, due to his common and extended use, this file is automatically linked by the compiler as if ...
- 1,369
3
votes
How should I take notes for the lectures?
you don't have to do that because there are already notes for each lecture in a PDF form which you can find under each lecture video in edX.
you may still want to take your own notes (maybe even on ...
3
votes
Accepted
Do we need to return 0 in C?
Typically and according to the standard, the return value of main should be of type int which obviously means that you should return an int value from main.
However, you don't really have to do that ...
- 17.4k
3
votes
Accepted
hello.c when I want to run it says:No such file or directory
I suppose this is your hello-world program
#include <stdio.h>
int main(void)
{
printf("hello, world\n");
return 0;
}
which is SAVED as hello.c in your Dropbox folder. Use the ...
- 3,326
3
votes
Accepted
Is there a mistake in the slides of Section 1?
According to this wikipedia entry:
The number 0 is neither positive nor negative and appears in the middle of a number line.
So asking for a positive number does in fact exclude zero.
- 2,625
2
votes
Accepted
Trying to compile f2c.c from walkthrough week1 without success
You are in the wrong directory, change the directory to where your file is stored i.e. Desktop here
jharvard@appliance (~) : cd ~/Desktop
jharvard@appliance (~) : make f2c
jharvard@appliance (~) : ./...
- 3,326
2
votes
Accepted
Where is the CS50 style guide document?
Styles are important because they specify good coding habits, which gives you comfort when working in a team, as everyone would be following the same convention, so it will be easier for others to ...
- 3,326
2
votes
Accepted
Can't use get_long_long();
Does cs50.h have a function called get_long_long?. There is no function by that name listed in the CS50 Reference. And notice this from the spec:
Now, get_long itself will reject hyphens (and more) ...
- 26.9k
1
vote
Accepted
Week 1 Credit; Not Creating Variable
The program is stuck in an infinite loop. Look at the while loop setup:
while(credit_number >= 0) // runs the loop until the credit card number is l
{
i = credit_number % 10; credit_number = ...
- 64.2k
1
vote
Accepted
how do i write pesudocode.txt for Mario? (less comfortable)
You make a new file by clicking the green plus sign at the top, next to where it says the name of the file you are currently on. On your keyboard, then do command shift S. It will give you options for ...
- 67
1
vote
Else If Boolean Statements of Equality In the Case of Complex Numbers
That example doesn't say what data type x and y are, but generally you can assume that numerical variables are real numbers in programming, unless specified otherwise.
There is a way to work with ...
- 709
1
vote
Accepted
Transform function into a loop or similar
Its good that you're thinking about how to make the code more efficient. Kudos to you!
Yes, repeating code is a red flag that things can be simplified. But here, the code is very similar but not the ...
- 64.2k
1
vote
Week 1 cash.c assignment: How can I get a variable to mutate as it gets operated on?
About the first error in line 10 , you cant declare a vatiable twice , you can only assign it more than once , so you need to delete the float type declaration which is inside the do while loop.
When ...
- 11
1
vote
Accepted
get_int variable in mario causing errors
It's an issue called variable scope, something that will be explained later. Simply put, a variable only exists within the surrounding pair of curly braces where it is created.
In Prof. Malan's ...
- 64.2k
1
vote
Accepted
Week 1: get_int & get_string errors
Solved!
I ran "update50" in the terminal twice, and after the second time a prompt came up that told me I'm currently running "pip 9.0.1" and there is an update available for "pip 10.0.1", and told ...
- 19
1
vote
Week 1: get_int & get_string errors
Your line numbers in code and in the error messages don't match, are off by one, so I'd guess you forgot to save, or compiled something else (another file, maybe of the same name in a different ...
- 20.7k
1
vote
Accepted
Switch(c) undeclared identifier
Simply put, c doesn't exist because it was never declared, and no value has been assigned to it. I could explain in detail, but the following site has already done it very nicely, including an ...
- 64.2k
1
vote
Can't compile adder from week 1
It's a syntax error. A comma is missing before the z in line 11.
- 64.2k
1
vote
1
vote
Last program from the first half of the lecture in week one?
Follow the link in the source code to the ioccc page. Follow some of the links to find out what it's all about. It's very cool. Then search the original page for "thad" (it's a winning entry from 2000)...
- 26.9k
1
vote
Accepted
Why does PrintName return void?
Good question. There is no requirement to capture a return value. Just because a function returns a value doesn't mean that the calling code needs to do anything with it. For many functions, like ...
- 64.2k
1
vote
why is no "\n" needed after GetString?
When you run this program, you indicate to the computer that you are finished entering your name by doing something. That "something" is where the new line in question comes from.
- 26.9k
1
vote
Accepted
CS50 Appliance compiling error!
Say you have written a program named example.c
First you compile your program like so
make example
Then you run it like so
./example
I tell you these because I see you have tried many times to do ...
- 7,326
1
vote
Accepted
Week 1 - Conditions - error expression result unused (expect ; at end of if else)
The if/else if/else conditions are used in the following way:
Single condition
if (condition)
{
// code to execute
}
Double condition
if (condition)
{
// code to execute
}
else
{
// ...
- 7,326
1
vote
Week 1 - Conditions - error expression result unused (expect ; at end of if else)
else is your last resort kind of command its like
if this then
{
do this
}
or
else if this then
{
do that
}
and finally when you cant think of any other condition you say you know what MR ...
- 169
1
vote
week 1 get 4 errors when compiling hello-1
Have you watched the lectures and/or the sections for week 1? Being able to research the correct syntax is a vital skill.
The data you pass to printf must be encapsulated in parentheses.
printf ( "...
- 42
1
vote
Permission Denied in pset1
Actually, you don't really have a problem. You just need a little instruction on a couple of nuances that you're tripping on.
First, make is saying up to date because the output of the compiler, file ...
- 64.2k
1
vote
CS50 commands, standard commands - is there any literature and who did that?
Some of the "Shorts" in Week 0 and Week 1 dip a little into this (not much!) but they do provide a little insight into where you can go and do further research to find out the answers you may be ...
- 667
Only top scored, non community-wiki answers of a minimum length are eligible