I want to perform a mathematical operation from values in a string

Question

string resistance;
ifstream in;
in.open(filename);
while (!in.eof())
{
    getline(in, resistance);
    cout << resistance <<endl;
}
in.close();

That is the code im using to read from the file. The output from the file is: for example:

10 25 10 60 45 35

10 45 23 45 65 88

I want to take each line and perform a mathematical operation by each each value of the line to a variable

You should be using `while (getline(...))`, but it sounds like you want a call to `std::accumulate`? — chris, Mar 30 '14 at 18:35
possible duplicate of [I want to perform a computation from a data file](http://stackoverflow.com/questions/22748475/i-want-to-perform-a-computation-from-a-data-file) — johnsyweb, Apr 01 '14 at 22:05

score 0 · Answer 1 · edited May 23 '17 at 12:20

0

First, split the string, then convert those to numbers using atoi, then loop through those values are performing the operations.

edited May 23 '17 at 12:20

Community

1
1

answered Mar 30 '14 at 18:42

Liam McInroy

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score 0 · Answer 2 · answered Mar 30 '14 at 18:44

0

in C++11 you can use std::stoi function:

istringstream iss( resistance);
istream_iterator<string> it = iss.begin();
while( it != iss.end()) {
    int value = stoi( *it++);
    //... do something
}

answered Mar 30 '14 at 18:44

4pie0

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I want to perform a mathematical operation from values in a string

2 Answers2