I have this project where we have to convert a made up simple coding language given through a txt into a c++ language and currently I am having a problem with checking my work through linux (where it will be tested on). On the other hand Visual Studio where I wrote my code works how it should be.
From what I observed something weird is going on when I am taking each line in the text, separating each word and placing it in a vector. How I do this is by starting with an empty string, looking at each character of the line, and when I see a space or a tab or any kind of character that signifies a separator then I push back that string to a vector then make the string empty again for the next characters. So something line "STR man = bloo" turns into <"STR", "man", "=", "bloo"> and so on.
In visual studio it worked like this, but it seems like in linux.. somehow the second element seems to add a weird character which would be "man ". Its not a space or an empty line and when I tried to look at size with a format std::cout << name << ":" << size << std::endl, it couts not the right format or result.
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Looking at visual Studio.
first line: "size" how many elements in that vector.
second line: is a name that I want to check if its already in a vector along with the length of that name
third line: shows all the elements in that vector (which should only show 1 since the size is 1) along with its length as well.
Looking at the linux result
-first line: "size" equals 1. Which is right
second line: the name im checking and its length, which is right
third line: is where the problem occurs. The name is 1 character greater than what it is suppose to be and instead of adding onto whats printed out, it replaces the first 3 letters instead?
fourth line: should not even happen because the size is only 1 and its a basic for loop of (int i = 0; i < size; i++)
Ive tried to use brute force and just pop back the last character of the second element causing my visual studio code to fail the tests but that still fails the conditional of if the name is = to the name in the vector (which should be true) in linux. Whatever character I add on the second element when I cout that value, such as << name << "." << endl; it seems to always go and replaces first letters of that string.
Pls help
Sorry for the delay, the problem was that I was not handling invisible characters such as \r.
Related
Sorry, the wording for the actual question is probably wrong. I have a program that reads in a line from a .txt file and then puts the string into an object to compare it to a string entered by the user. I haven't been able to get it to match, and when I've tried to see what is entered, I don't see much. Maybe there's an invisible character denoting the end of the line? I've tried code like this:
std::cout << "...." << table[row][col]->get() << "...." <<std::endl;
And got
....a
as the result. When reading the file I used std::getline() if that makes a difference.
I didn't find a true fix, although I did see that the length of the read-in string was one int longer than the actual word. I was able to use a substring to cut the end off of the string.
I'm trying to fill text document, but when I do - I get first line blank.
My text document, I'm reading from, looks like this:
3
first fr random 5
second 9
third shazam 2
I've tried removing first value and so blank line went away. So it correlates, but I need that value.
// My code
ifstream in("U2.txt");
ofstream out("U2.txt");
int n;
in>>n;
char vardaiStart[n][21];
in.read(vardaiStart[0], 21);
out << vardaiStart[0]<< endl;
output looks like this:
*blank*
first fr random
but what I want is:
first fr random
So, in other projects I won't be using old C since now, but for this project I red that [endline] and ignored it like this: in.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
Your input file looks like:
3[endline]
first fr random 5[endline]
second 9[endline]
third shazam 2[endline]
Note the [endline] I added: they can be '\n', '\r\n' depending on the system that generated the file.
Your first instruction is:
in >> n;
a formatted input read: you are asking to read an integer from the file, so only characters that can form valid integers will be read.
This means that after that instruction the remaining portion of the file will be:
[endline]
first fr random 5[endline]
second 9[endline]
third shazam 2[endline]
The rest of your code reads raw bytes, so it will read the first [endline] as well (and print it).
As other suggested in the comments, you should not be using variable length arrays as they are not part of any C++ standard (but part of the C one). Try to use the C++ standard library instead.
I was trying to test my classes when I encountered a weird problem in the input of test cases.
I tried to simplify the input to see what went wrong so I created the program below.
#include <iostream>
#include <string>
int main()
{
std::string number;
while (std::getline(std::cin, number))
{
std::cout << std::string(number) << " ";
}
}
Basically, I am getting each line of text and storing it in a string variable using getline(). Then I display each string using std::cout and append a single space character.
My input file contains this:
one six
one seven
The expected output should be like this:
one six one seven
But instead, I get this:
one seven
That is a space character followed by the second line of the input. It disregards the first line of input. I know for a fact that each line are being read properly because they were correctly displayed when I replaced the code with this:
std::cout << std::string(number) << std::endl;
This error is quite new to me. What's happening here? Can anybody explain? TIA!
Ok, its clear.
Your input file must be : one six\r\ntwo seven\r\n with normal Windows EOL.
When you read it under cygwin, you get in first read one six\r, only the \n being eaten by getline, and same one seven\r on the second line.
So you write : one six\r one seven\r (with an ending blank). But the \r alone put the curson back in first column of same line and second line erases first.
And normally the problem is not visible if you replace the ending blank by a std::eol that puts the cursor on a new line. The tab (\t) if really a special case : it put the cursor on eighth column exactly where you expect it, but by pure chance. If you invert the two lines it would be more apparent because you would see the remaining of first line at end of second.
You can confirm it by writing the output to a file and editing it.
I could reproduce it under Linux with a Windows EOL. The reason for that is that Cygwin closely mimics Unix-Linux and use Unix EOL convention of only \n.
first of all thanks for reading ^ ^
ok, so I'm making an easy menu for a console project
after I created the options I wanted to add the char(240) as another option but I can't figure out how to declare it I cant just write ≡ because Dev++ won't let me write it, the code is:
char *menu_list[6] = { " SYMBOL GOES HERE "," View ", " Edit ", " Search ", " Reset", " Quit " };
does anyone know how to do this? or if I'm doin it all wrong, can you tell me the right way to do it?
i'm forced to make it work on windows, i can
cout << char(240);
and it works right, but I cannot store that same symbol into menu_list
also I got the code from here
http://www.theasciicode.com.ar/extended-ascii-code/hyphen-ascii-code-240.html
There was a deleted answer that had the correct response: use "\xf0" to represent the character.
Ordinarily you would need to know which code page is being used by Windows to know how a character code maps to a particular character on screen. However by doing the research yourself, you already know that the decimal value 240 represents the character you need. That decimal 240 is the same as hex f0, and the way to embed a hex literal value in a string is to prefix it with \x.
As noted in the link you posted, these codes correspond to code page 437. This is the one used by the command window in English versions of Windows; I'm not sure if alternate language versions of Windows use anything different. Calling this "extended ASCII" is confusing, since there have been many attempts to extend ASCII over the years and none of them are the same.
Yeah so ive tried lots of stuff but the output keeps coming out all messed up. Heres a picture showing whats going on. As you see the letter variable gets all weird.
The problem is that "letter: " + letter" doesn't do what you think it does, it adds the integral value of letter to the const char* string literal "letter". Easiest fix is string("letter: ") + letter.