how to convert characters of a string to integer in c++ code example

Example 1: integer to char c++

// for example you have such integer
int i = 3;

// and you want to convert it to a char so that
char c = '3';

what you need to do is, by adding i to '0'. The reason why it works is because '0' actually means an integer value of 48. '1'..'9' means 49..57. This is a simple addition to find out corresponding character for an single decimal digit integer:

i.e. char c = '0' + i;

If you know how to convert a single decimal digit int to char, whats left is how you can extract individual digit from a more-than-one-decimal-digit integer

it is simply a simple math by making use of / and %

int i = 123 % 10;  // give u last digit, which is 3
int j = 123 / 10;  // give remove the last digit, which is 12
The logic left is the homework you need to do then.

Example 2: c++ convert const char* to int

#include <iostream>
#include <sstream>

const char* value = "1234567";
stringstream strValue;
strValue << value;

unsigned int intValue;
strValue >> intValue;

cout << value << endl;
cout << intValue << endl;