Convert Char Array to an integer in C++

Convert Char Array to an integer in C++ – thisPointer

This tutorial will discuss about a unique way to convert char array to an integer.

In C++, the string.h header file provides a function stoi(). It accepts a character pointer as an argument, and interprets its contents as an integer value. It returns an int value. We can use this function to convert a char array to integer.

If the given string can not be converted into an integer value or its out of range, then it will raise an exception i.e. either invalid_argument or out_of_range exception. Therefore, while using the stoi() function for converting a char array to int, we need to make sure that we catch all the exceptions.

Let’s see the complete example,

#include <iostream>
#include <string.h>

// Returns true, string is successfully conveted
// to integer
bool ConverToInt(const char* arr, int& value )
{
    bool result = false;
    try
    {
        // convert char array to string
        value = std::stoi( arr);
        result = true;
    }
    catch( const std::exception& )
    {}
    return result;
}

int main()
{
    char arr[10] = "234";
    int value = 9;

    // Convert char array to integer
    if(ConverToInt(arr, value) )
    {
        std::cout<<"Integer Value is : " << value << std::endl;
    }
    else
    {
        std::cout<<"Char Array can not be converted to an integer \n";
    }

    return 0;
}

Output :

Integer Value is : 234

Summary

Today we learned about several ways to convert char array to an integer. Thanks.