CODEWITHSUNDEEP
c++stringstream
Will Nasby
Will Nasby

Reputation: 1148

Converting a string to an int

I'm getting random numbers after running the line convert >> quarter, I figure I have to clear stringstream out before I run it to convert again, but how would I go about doing that? And could someone explain what's going on during: (I found this as a solution but don't quite understand it)

    stringstream convert(tokens[1]);
    convert >> quarter;

-

Play parse(string toParse){
    vector<string> tokens;
    string play = toParse;
    string oName, dName;
    int x, quarter, minutes, down, yardstogo, startloc, playdesc;
    for(int y=0; y<10; y++){
        x = toParse.find(",");
        tokens.push_back(toParse.substr(0,x));
        toParse = toParse.substr(x+1);
    }
    stringstream convert(tokens[1]);
    convert >> quarter;
    convert.str(tokens[2]);
    convert >> minutes;
    convert.str(tokens[6]);
    convert >> down;
    convert.str(tokens[7]);
    convert >> yardstogo;
    convert.str(tokens[8]);
    convert >> startloc;
    playdesc = findPlay(tokens[9]);
    Play a(quarter, minutes, tokens[4], tokens[5], down, yardstogo, startloc, playdesc, play);
    return a;
}

Thank you.

Upvotes: 1

Views: 163

Answers (3)

erlc
erlc

Reputation: 680

You could just use the <string> function stoi (C++11)...

quarter = stoi(tokens[1])

Upvotes: 0

Oli_G
Oli_G

Reputation: 510

You should probably use the atoi() function wich is faster than the stringstream conversion method.

Like so:
quarter = atoi(tokens[1].c_str());
minutes = atoi(tokens[2].c_str());
...

Regards

Upvotes: 0

David Norman
David Norman

Reputation: 19879

If you keep doing it this way, you need to call clear() after calling str():

stringstream convert(tokens[1]);
convert >> quarter;                // Conversion 1
convert.str(tokens[2]);
convert.clear();
convert >> minutes;                // Conversion 2
...

The problem is that the first conversion reads the entire string, which means that it sets the iostate of the stream to eof. Calling str() does not reset the iostate. You have to do it manually.

In your code the iostate is eof on all the later conversions, so no conversion is even attempted.

Upvotes: 1

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