How to convert a character form a string to an integer?

Question

I need this to convert a number from binary to decimal, the number will be larger than 100 digits

Answer 1

Save the number in a string, and use this function like this (from <sstream>):

#include<iostream>
#include<sstream>
using namespace std;
int main(void)
{
long int value;
char str[1000]="1010110101010110110111011";
stringstream(str)>>value;
cout<<value<<endl;
}

Answer 2

But i dont know why is it automatically converting binary to decimal :)

Answer 3

But i dont know why is it automatically converting binary to decimal :)

Answer 4

only for nos as large as this...

Answer 5

your welcome ! if you had problem consider me as your firiend ! :)

Answer 6

bourhan ! your code is wrong ! you cant convert string to int directly ...

Answer 7

Catalin read this code :
http://www.sololearn.com/app/cplusplus/playground/cHE1eL0C6sWG/

Answer 8

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

int main() {

// a string variable :
string s;

cin >> s;

// an array of integers for storing numbers :
int numbers[1000];
int j = 0;

for (int i = 0;i<s.length();i++)
{
if ((int)s[i] >= 48 && (int)s[i] <= 57)
{
j++;
numbers[j] = ((int)s[i] - 48);
}
}

//output numbers :
if (j != 0)
for (int i = 1;i <= j;i++)
cout << numbers[i] << endl;

return 0;
}

Answer 9

@Amir Goodarzi I don't want to convert a string to int, I want to convert a char from inside a string to int, and this can be done from what I heard

Answer 10

@Bourhan that doesn't work properly, sorry :(

Answer 11

I think I got it, thank you @Amir