How to parse a string to an int in C++?
You can use a string stream to parse an int in c++ to an int. You need to do some error checking in this method.
example
#include<iostream>
#include<sstream>
using namespace std;
int str_to_int(const string &str) {
stringstream ss(str);
int num;
ss >> num;
return num;
}
int main() {
string s = "12345";
int x = str_to_int(s);
cout << x;
}Output
This will give the output −
12345
In the new C++11, there are functions for that: stoi(string to int), stol(string to long), stoll(string to long long), stoul(string to unsigned long), etc.
Example
You can use these functions as follows −
#include<iostream>
using namespace std;
int main() {
string s = "12345";
int x = stoi(s);
cout << x;
}Output
This will give the output −
12345
Published on 28-Feb-2018 11:14:15
