Question

I have a vector of strings. Need help figuring out how to convert it into vector of integers in order to be able to work with it arithmetically. Thanks!

#include <iostream>
#include <string>
#include <vector>
using namespace std;

int main(int argc, char* argv[]) {

    vector<string> vectorOfStrings;
    vectorOfStrings.push_back("1");
    vectorOfStrings.push_back("2");
    vectorOfStrings.push_back("3");

    for (int i=0; i<vectorOfStrings.size(); i++)
    {
        cout<<vectorOfStrings.at(i)<<endl;
    }

    vector<int> vectorOfIntegers;

    //HELP NEEDED HERE
    //CONVERSION CODE from vector<string> to vector<int> 

    int sum;
    for (int i=0; i<vectorOfIntegers.size(); i++)
    {
        sum += vectorOfIntegers.at(i);
    }
    cout<<sum<<endl;
    cin.get();

    return 0;
}

Answer 1

There are mulitple ways of converting a string to an int.

Solution 1: Using Legacy C functionality

int main()
{
    //char hello[5];     
    //hello = "12345";   --->This wont compile

    char hello[] = "12345";

    Printf("My number is: %d", atoi(hello)); 

    return 0;
}

Solution 2: Using lexical_cast(Most Appropriate & simplest)

int x = boost::lexical_cast<int>("12345"); 

Surround by try-catch to catch exceptions.

Solution 3: Using C++ Streams

std::string hello("123"); 
std::stringstream str(hello); 
int x;  
str >> x;  
if (!str) 
{      
   // The conversion failed.      
}