3
votes
Accepted
PSET 3 Runoff Error: variable length array declaration not allowed at file scope
int voter_count, candidate_count;
candidate candidates[candidate_count];
In C, you cannot define an array with a variable size at a global scope (even if you could, candidate_count does not have a ...
- 950
2
votes
Selection Sort: Holes in Logic
The main problem is in the following statements:
string answer = 0;
answer[i]= min_value;
Let's see if I can explain it clearly;
a variable of type string is really a typedef (an alias in other ...
- 5,201
2
votes
Arrays and their sizes in C
strlen takes a pointer value, a memory address, and from this memory location counts the bytes until it hits one of value 0 (in this context often called "null terminator"). Since array2 does not ...
- 20.9k
2
votes
Accepted
What happens when you assign a character string to a char* instead of writing element by element?
I'll let you visualize this for yourself. Go here http://www.pythontutor.com/c.html#mode=edit and paste your code, then hit "visualize execution".
You'll see graphically what's happening in memory.
...
- 2,595
2
votes
Accepted
Lecture 2 Arrays
The error you are getting is not saying that you are passing a double instead of a float, but that a double is expected. You are passing average, which is not a variable but a function. Your prototype ...
- 1,882
1
vote
Accepted
Problem understanding array with Caesar project
argv[1] is a string and each char in the string is index 0, 1, 2....etc. The correct notation is argv[1][0], argv[1][1], argv[1][2]..... etc.
- 27.6k
1
vote
Passing arrays into function in tideman
ranks[] means an array of values that has been named ranks; from the declaration, we can tell that the values will all be integers. Any time you see a name followed by square brackets in C-based ...
- 1,882
1
vote
Accepted
runtime error in sandbox for array examples from week 2 lecture
When the int array scores is declared here int scores[n]; it will have n elements, indexed to 0. When 3 is entered, the elements of scores are scores[0], scores[1] and scores[2]. There is no scores[3]....
- 27.6k
1
vote
Accepted
I'm getting an for error expected expression. What exactly I'm I doing wrong?
First of all, this is why it's important to get the indentation aligned correctly so you can see what goes with what. Here's the corrected indentation.
int main(int argc, string argv[])
{
if (...
- 67.4k
1
vote
Accepted
Trouble modifying elements of an array of candidates in Plurality
candidate zero = candidates[0];
creates a new variable of type candidate and copies over the value from candidates[0]. The new variable gets its initial value from candidates[0], but is not connected ...
- 20.9k
1
vote
Accepted
PSET 4 Resize: Pointers, arrays and file IO
You have an infinite loop because of a typo that is writing to the output file until the system kills it because it has used up the disk space allotment. I'll let you figure out the typo, but it's ...
- 67.4k
1
vote
Clarification regarding for loops and arrays
Rob was demonstrating the use of a for loop to load values into an array. The i doesn't stand for anything. It is simply a counter for the for loop. It is a standard and common practice to use a ...
- 67.4k
1
vote
[pset2][Vinegere] Code not enciphering text after certain letters, please help!
The problem is in the names of your variables: As most of the names have no meaning, it is difficult to keep track of the meaning for each of these variables.
In this case, your variable h makes ...
- 999
1
vote
Accepted
Why string variable has no square bracket?
The reason why a string variable does not have brackets, is because it is not a string array. (It is a char array or a char pointer.)
In fact, string is a new type, defined in the cs50 library. It ...
- 999
1
vote
Pset1: Error when trying to assign single digits of int variable to array using for loop
A simple way is a loop over a copy of the number. number % 10 returns the last digit, while number / 10 returns the number with last digit removed. Remove digits from the copy until it's less than 100 ...
- 20.9k
1
vote
Accepted
Pset2: Copying string contents
You declare ky as string[keylen], it should be char[keylen+1] (don't forget the null terminator, that's why +1).
Don't forget to check argc before accessing argv[1], it might not exist at all.
Don't ...
- 20.9k
1
vote
Accepted
Error handling while running credit.c for pset1
int c = 0;
........
int numberArray[c];
By doing this you declare int numberArray[0] that is an array of zero members. So any index is "out of bounds" of this array, that is the mistake you see. ...
- 1,139
1
vote
Accepted
Finding & printing character after space in string in C
the isspace function should return a boolean, whereas you assign a char to the 'return value' of isspace. What you probably want to do is to check if, for every i, the current name[i] is a space, and ...
- 102
1
vote
Accepted
Pset7 - Portfolio: $positions not filling
Oh. My. Goodness. My 2nd test condition wasn't a valid stock (just some random capital letters that I thought looked like an actual stock symbol) so
if ($stock !== false)
would kill the foreach() ...
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