Using files to store data in C++

[jerry]

Hey,

I'm still a beginner trying to get my basics right, so please have patience with me.

I'm trying to store values from the user into a file in the following way:

while(count<5)

{

cout<<"Enter values: ";

outData << value;

count++;

}

However I am getting a warning the "value" wasnt defined. Anyway can anybody help me with this ?

P.S. I am declaring the file streams correctly, using the correct header file etc.,

Thanks !

[OPaul]

You have to declare and probably initialize value first. Something like;

int value = 0;

[jerry]

If I do that then the file is being filled with all zeros. I'll try that again now.

EDIT: Yes, its getting filled with zeros.

Any ideas what I should be doing ? :unsure:

Edited March 16, 2004 by jerry

[OPaul]

Oh, nevermind value is your file, gotcha.

[azcodemonkey]

You need to get the value from the keyboard stream first then write it to file.

[+virtorio MVC]

Looks to me that you are never reading in any data. Try this

int value;     // for numbers or
char value;  // for letters/charactors

while(count<5)
{
cout<<"Enter values: ";
cin >> value;
outData << value;
count++;
}

That may be what you are looking for

[John Veteran]

  virtorio said:

Looks to me that you are never reading in any data. Try this

int value; ? ? // for numbers or
char value; ?// for letters/charactors

while(count<5)
{
cout<<"Enter values: ";
cin >> value;
outData << value;
count++;
}

That may be what you are looking for

Virtorio's code will wo(Y)(Y) Just make sure you only declare value on;) ;)

[jerry]

thanks virtorio ! & gameguy, yes I declared it once. ;)

I have another question now;

I'm trying to access the same file using "inData" with proper parameters but I'm only able to access the last value. How do I get to the beginning of the file ?

Thanks

[OPaul]

Either reopen it or you can use the rewind() function.

[jerry]

I closed it and reopened it the following way:

outData.close(); //Closing the file.dat after writing values into it.

inData.open("file.dat //Reading values from file.dat

I dont know how to use the rewind function. I was also trying seekg but that is isnt working. I am doing something wrong with the syntax, i think.

[OPaul]

inData.rewind() I'm assuming

[jerry]

inData.rewind();

It doesnt work, just tried. Get an error message saying that "rewind" is not a member of basic_ifstream ... :(

[+virtorio MVC]

This is a stupid question but I have never handled files this way before.

If you tell me the data type of the " inData" varible I might be able to help you.

[jerry]

the data type of "inData" variable is int.

I'm trying to get data(integer data) from the user and store them in a file. Next I've to operate on the values entered into the file.