Thread: Need help with writing to file

Why are you trying to open the same file twice? And why aren't you opening the file in the constructor:

Code:

ifstream inputFile("Randoms.txt");

The following line is incorrect for a couple of reasons

Code:

    for(int index=0; t; index++);

First the condition section is malformed, it should have some kind of comparison operation. Also you should get into the habit of using braces with your condition statements, only one of those lines would be executed inside the loop. That is if the statement didn't terminate with the semicolon.

Also in future you may want to actually ask a question.


Jim

how do i check to see if the file actually got written to?

I would say it probably didn't get written. First you can't write to an input stream. Second input streams, with the default open arguments, will not create a file if the file doesn't exit.

You should always check to see that your files open properly. You may want to study the following tutorial: File IO

To actually check, you should view the programs working directory to see if the file exists.

Jim

Originally Posted by jimblumberg

I would say it probably didn't get written. First you can't write to an input stream. Second input streams, with the default open arguments, will not create a file if the file doesn't exit.

You should always check to see that your files open properly. You may want to study the following tutorial: File IO

To actually check, you should view the programs working directory to see if the file exists.

Jim

alright i see it now! now how do i write the random numbers to it

Originally Posted by gevans

how do i check to see if the file actually got written to?

Go to the location of the file and open it.After opening the file check whether the file is open before trying to write to it.You can check this link for a rough idea of how you should go about it,..A development process

You are not checking whether your file is open.
You are also opening the file twice.
Try doing something like this:
while(inputFile.good()){
for(int index=0; index<t; index++)
random = (rand()%1000)+1;
inputFile << random << endl;
inputFile.close()

how do i get more than one random number to output in a file

Usually by printing more than one number to your file. Think about looping.

You need to find an indentation style you like and use it consistently. This will make reading your code much easier.

Jim

im lost guys.....its not working

Code:

#include <iostream>
#include <string>
#include <iomanip>
#include <ctime>
#include <fstream>
#include <cstdlib>


using namespace std;
int Validate();


int main()
{
	int t;
	int random;
	ofstream myFile;
  myFile.open ("example.txt");
    
while(myFile.good())
for(int index=0; index<t; index++)
random = (rand()%1000)+1; 
myFile << random << endl; 
myFile.close();
  return 0;
}


int Validate()
{
	int t;
	do 
	{
	cout << "How many numbers to write?"<< endl;
	cin >> t;
	}
	while (t <50 || t >1000);
	return (t);
}

still not working

Code:

#include <iostream>
#include <string>
#include <iomanip>
#include <ctime>
#include <fstream>
#include <cstdlib>
 
 
using namespace std;
int Validate();
 
 
int main()
{
	int random;
     float t;
    ofstream myfile;
  myfile.open ("example.txt");
   
     while(myfile.good())
for(int index=0; index<t; index++)
random = (rand()%1000)+1; 
myfile << random << endl;
 
 
  myfile.close();
  system("pause");
  return 0;
}
 
 
int Validate()
{
    int t;
    do
    {
    cout << "How many numbers to write?"<< endl;
    cin >> t;
    }
    while (t <50 || t >1000);
    return (t);
}

You have not initialized the valiable t,...m?

i give up!