using data in a file

So I am taking an intro to programming course, and I have one problem that I haven't been able to solve. This is using the <fstream> library:

Given a text file, I need my program to use the data in it to perform certain operations. I've figured out how to read and echo the file, but I don't know how to use it to perform calculations. Example, I would like to find the average of the numbers in the lines containing 'M' (for male):

Code:

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Bailey          M CC 68
Harrison        F CC 71
Grant            M UN 75

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How would I make my program get just the numeric input from the lines with an 'M', so that I can find their average?

Quote:

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How would I make my program get just the numeric input from the lines with an 'M', so that I can find their average?

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1. Read one row from file and store in a CString variable.
2. Use CString::Tokenize to extract 2nd and 4th value to local string variables
3. Compare if 2nd value is 'M', if yes then further convert 4th value to integer
4. Do further calculations here
5. Repeat step 1

Or if you don't want to use CString, have a look at this thread.

Hi!
What is wrong with strtok ? it always works fine for me.

Regards,
jibeiuvia!

Quote:

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Originally Posted by AtillaTheHun

So I am taking an intro to programming course, and I have one problem that I haven't been able to solve. This is using the <fstream> library:

Given a text file, I need my program to use the data in it to perform certain operations. I've figured out how to read and echo the file, but I don't know how to use it to perform calculations. Example, I would like to find the average of the numbers in the lines containing 'M' (for male):

Code:

---

Bailey          M CC 68
Harrison        F CC 71
Grant            M UN 75

---

How would I make my program get just the numeric input from the lines with an 'M', so that I can find their average?

---

Ok, take it easy man! :)
if you like fstream, then you have to learn about input stream and output stream,
I'd prefer stringstream of sstream :( if I were you.

-Antonio

Quote:

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Originally Posted by ckweius

1. Read one row from file and store in a CString variable.
2. Use CString::Tokenize to extract 2nd and 4th value to local string variables
3. Compare if 2nd value is 'M', if yes then further convert 4th value to integer
4. Do further calculations here
5. Repeat step 1

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This is the non-visual C++ forum.

For a simple input file like that, you can just read
directly into the appropriate typed variables:

Code:

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// assuming the ifstream object is : in

string name , sex , code;
int      num;

while (in >> name >> sex >> code >> num)
{
    // process the line
}

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For more complex cases, reading line by line, placing into a stringstream,
and using it to gte the input is a better way to go (as mentioned in
previous posts).

Also, it is usually easier to do error checking in the line by line method.

Quote:

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Originally Posted by AtillaTheHun

So I am taking an intro to programming course, and I have one problem that I haven't been able to solve. This is using the <fstream> library:

Given a text file, I need my program to use the data in it to perform certain operations. I've figured out how to read and echo the file, but I don't know how to use it to perform calculations. Example, I would like to find the average of the numbers in the lines containing 'M' (for male):

Code:

---

Bailey          M CC 68
Harrison        F CC 71
Grant            M UN 75

---

How would I make my program get just the numeric input from the lines with an 'M', so that I can find their average?

---

You can
use getlline to read each string into a vector of strings and process each line/string in the vector after that.


- I am sorry if my help doesnot help you, I feel sorry for that only. It's my happiness to post help you, mustab man on atilla. :)

Quote:

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Originally Posted by AtillaTheHun

So I am taking an intro to programming course, and I have one problem that I haven't been able to solve. This is using the <fstream> library:

Given a text file, I need my program to use the data in it to perform certain operations. I've figured out how to read and echo the file, but I don't know how to use it to perform calculations. Example, I would like to find the average of the numbers in the lines containing 'M' (for male):

Code:

---

Bailey          M CC 68
Harrison        F CC 71
Grant            M UN 75

---

How would I make my program get just the numeric input from the lines with an 'M', so that I can find their average?

---

Hello, I write code in C# only, you can
read the file into a string easily
str=File.ReadAllText(filename);
str.Tokenize(provide delimiters[])
then you can check match condition eaiser

You can do it yourself!