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I tried to write a little program that retrieves data from a .txt file and shows it in the terminal but I got an error. I have to say I am new to visual studio; until now i worked on code:blocks

I have tried the suggestion from the error code, adding the #include "pch.h" at the beggining but it still didn t work.

The error code is C1010 (if i build the code without line #include "pch.h"); If i build it with that line i recieve multiple error codes: 

"1>c:\users\bogdan\documents\c & c++ programs\writing and reading a txt file\writing and reading a txt file\writing and reading a txt file.cpp(10): error C2065: 'ifstream': undeclared identifier 1>c:\users\bogdan\documents\c & c++ programs\writing and reading a txt file\writing and reading a txt file\writing and reading a txt file.cpp(10): error C2146: syntax error: missing ';' before identifier 'inFile' 1>c:\users\bogdan\documents\c & c++ programs\writing and reading a txt file\writing and reading a txt file\writing and reading a txt file.cpp(10): error C2065: 'inFile': undeclared identifier 1>c:\users\bogdan\documents\c & c++ programs\writing and reading a txt file\writing and reading a txt file\writing and reading a txt file.cpp(11): error C2065: 'inFile': undeclared identifier 1>c:\users\bogdan\documents\c & c++ programs\writing and reading a txt file\writing and reading a txt file\writing and reading a txt file.cpp(11): warning C4129: 'B': unrecognized character escape sequence 1>c:\users\bogdan\documents\c & c++ programs\writing and reading a txt file\writing and reading a txt file\writing and reading a txt file.cpp(11): warning C4129: 'D': unrecognized character escape sequence 1>c:\users\bogdan\documents\c & c++ programs\writing and reading a txt file\writing and reading a txt file\writing and reading a txt file.cpp(14): error C2065: 'inFile': undeclared identifier 1>c:\users\bogdan\documents\c & c++ programs\writing and reading a txt file\writing and reading a txt file\writing and reading a txt file.cpp(15): error C2065: 'cout': undeclared identifier" #include "pch.h" #include <iostream> #include <fstream> #include <string> int main() { ifstream inFile; inFile.open("C:\Users\Bogdan\Documents\UID.txt"); int x; inFile >> x; cout << x; return 0; }
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    please let is know what the error code / text is. Commented Feb 7, 2019 at 18:41
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    And you need to escape your \ so replace \ with \\ Commented Feb 7, 2019 at 18:42
  • Sorry, my bad, i forgot to tell that. The code is C1010 (if i build the code without line #include "pch.h"); If i build it with that line i recieve multiple error codes: Commented Feb 7, 2019 at 18:42
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    When asking about build errors, always include the actual errors, in full and complete, including any possible informational notes. And copy-pasted as text. So please edit your question to include that. Commented Feb 7, 2019 at 18:42
  • @Someprogrammerdude I rewrote my question Commented Feb 7, 2019 at 18:48

2 Answers 2

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ifstream and cout are both part of the std namespace. You aren't using namespace std, so you need to include the namespace whenever you reference them. A fixed version of your code would be:

#include <iostream> #include <fstream> #include <string> int main() { std::ifstream inFile; inFile.open("C:\Users\Bogdan\Documents\UID.txt"); int x; inFile >> x; std::cout << x; return 0; }
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Thank you, Brandon! I added this line: using namespace std; (because i am not used with std::) and now it works...partially; In the txt file i have the number 123 but in the output it is something like -880513. I ll fix this one myself :D Thanks for the help
That looks like an uninitialized int. I'd bet the file is failing to open, which usually means the file path is wrong.
You were right. I modifyed the file path and now it works perfectly!
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This is a small example in C++ show you how to open a file using fstream, after i add a loop while ( getline (myfile,line) ) that check if the filestream has a line, if it has a line then the program will print it cout << line << '\n'; if not the program will exit.

#include <iostream> #include <fstream> #include <string> int main () { string line; std::ifstream myfile ("/path/to/file.txt"); if (myfile.is_open()) { while ( getline (myfile,line) ) { std::cout << line << std::endl; } myfile.close(); } else std::cout << "Error unable to open file" << std::endl; return 0; }
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What have you changed? Why? Code-only answers encourages cargo-cult programming which is bad. Not to mention your program does a lot that the OP doesn't really ask about.
version without using using namespace std; to avoid pollutes the global namespace and increase compile time

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