CODEWITHSUNDEEP
c++stl
user466534
user466534

Reputation:

copy contents of vector into file

i have following code for copying content of vector into file

#include<iterator>
#include<algorithm>
#include<fstream>
#include<iostream>
#include<vector>
using namespace std;

void dump(vector<int>& v){
    ofstream out1("C\\Users\\datuashvili\\Desktop\\vector.txt");

    if(!out1){
        exit(1);
    }
    copy(v.begin(),v.end(),ostream_iterator<int>(out1," "));
}
int main(){

    ofstream out1("C\\Users\\datuashvili\\Desktop\\vector.txt");
    vector<int>v;
    v.push_back(100);
    v.push_back(200);
    v.push_back(300);
    v.push_back(500);
    v.push_back(1000);
    dump(v);

    return 0;
}

but when i simple run this code,,there is not written into file which is created on desktop,why?could you tell me what is wrong with this code? EDITED: here is edited code which also does not work doesn't open files and also does not write,two version 1.version

#include<iterator>
#include<algorithm>
#include<fstream>
#include<ostream>
#include<iostream>
#include<vector>
using namespace std;
void dump( vector<int>& v){
    ofstream out1(("C:\\vector.txt"));

    if(!out1){
        exit(1);
    }

    copy(v.begin(),v.end(),ostream_iterator<int>(out1," "));
    out1.close();
}
int main(){

    vector<int>v;
    v.push_back(100);
    v.push_back(200);
    v.push_back(300);
    v.push_back(500);
    v.push_back(1000);
    dump(v);

    return 0;
}

2.

#include<iostream>
#include<fstream>
#include<ostream>   
#include<vector>
#include<algorithm>
#include<iterator>
using namespace std;
template<typename T>
void writeTo(const std::string& filepath,const  vector<T>& data)
{

 ofstream filestream("C:\\vector.txt");
 std::copy(data.begin(),data.end(),std::ostream_iterator<T>( filestream," "));
 filestream.close();

}
int main(){

   vector<int>test;
   test.push_back(1);
   writeTo<int>("C:\\vector.txt", test);

   return 0;
}

Upvotes: 1

Views: 8481

Answers (3)

Robᵩ
Robᵩ

Reputation: 168716

I suspect the problem is this:

ofstream out1("C\\Users\\datuashvili\\Desktop\\vector.txt");

should be;

ofstream out1("C:\\Users\\datuashvili\\Desktop\\vector.txt");
               ^^^^^

You could have found this out on your own by running under a debugger, observing the exit status of your program, or by adding print statements to your program.

In a debugger, you would have stepped through your code and discovered that you hit "exit(1)". Alternatively, you could have added something like cout << "Can't open file!\n"; to your if statement.

Upvotes: 4

Jem
Jem

Reputation: 2275

Try to start with a simpler, working version, then change things one by one: this example will just create the file in c:/

#include <fstream>
#include <vector>
using namespace std;

void dump( const vector<int> & v)
{
    ofstream out1("C:\\vector.txt");

    if(!out1)
    {
        exit(1);
    }
    copy(v.begin(),v.end(),ostream_iterator<int>(out1," "));
}

int main()
{
    vector<int>v;
    v.push_back(100);
    v.push_back(200);
    v.push_back(300);
    v.push_back(500);
    v.push_back(1000);
    dump(v);
    return 0;
}

As other people mentioned, your path is wrong (at least, missing the ":" in "c:\..."), and you should open the file in only one place.

Upvotes: 3

codencandy
codencandy

Reputation: 1721

Like Rob commented your path is still wrong. You missed the colon after the disk identifier. Your path needs to be something like this: "c:\...."

And you still open the stream twice which on the second try might fail since this resource is locked by the first call.

Try someting like this:

template< typename T >
void writeToFile( const std::string& filePath, const std::vector< T >& data )
{
  std::ofstream fileStream( filePath );
  std::copy(data.begin(), data.end(), std::ostream_iterator< T >(fileStream, " ") );

  fileStream.close();
}

int main()
{
  ...

  vector< int > test;
  test.push_back(1);

  writeToFile<int>( "c:\\test.txt", test );

  ...
}

Upvotes: 0

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