how to change type of value char array to int in c++?

Question

I'm new to CPP.

I'm trying to create small console app.

my qustion is, is there a way to change char array to integer...?!

for example:

char myArray[]= "12345678" to int = 12345678 ...?!

tnx

Answer 1

You don't "change" a type. What you want is to create an object of a certain type, using an object of the other type as input.

Since you are new to C++, you should know that using arrays for strings is not recommended. Use a real string:

std::string myString = "12345678";

Then you have two standard ways to convert the string, depending on which version of C++ you are using. For "old" C++, std::istringstream:

std::istringstream converter(myString);
int number = 0;
converter >> number;
if (!converter) {
    // an error occurred, for example when the string was something like "abc" and
    // could thus not be interpreted as a number
}

In "new" C++ (C++11), you can use std::stoi.

int number = std::stoi(myString);

With error handling:

try {
    int number = std::stoi(myString);
} catch (std::exception const &exc) {
    // an error occurred, for example when the string was something like "abc" and
    // could thus not be interpreted as a number
}

Answer 2

Use boost::lexical_cast:

#include <boost/lexical_cast.hpp>

char myArray[] = "12345678";
auto myInteger = boost::lexical_cast<int>(myArray);

Answer 3

The atoi function does exactly this.

Answer 4

Apart from atoi() with C++11 standard compliant compiler you can use std::stoi().