Convert a hexadecimal number into decimal c++

To convert a hexadecimal number into decimal in C++, you can use the std::stoi function from the <string> library. Here's an example:

#include <iostream>
#include <string>

int main() {
    std::string hexNumber = "1A"; // the hexadecimal number
    int decimalNumber = std::stoi(hexNumber, nullptr, 16); // convert hexadecimal to decimal

    std::cout << "Decimal number: " << decimalNumber << std::endl;

    return 0;
}

Let's break down the code and explain each step:

1. Include the necessary libraries:

#include <iostream>
#include <string>

We include the <iostream> library for input and output operations and the <string> library for string manipulation.

1. Define the hexadecimal number:

std::string hexNumber = "1A";

We define the hexadecimal number as a string. In this example, the hexadecimal number is "1A".

1. Convert hexadecimal to decimal:

int decimalNumber = std::stoi(hexNumber, nullptr, 16);

We use the std::stoi function to convert the hexadecimal number to decimal. The function takes three arguments: the hexadecimal number as a string (hexNumber), a pointer to the location where the function stopped parsing (nullptr in this case), and the base of the number system (16 for hexadecimal).

1. Display the decimal number:

std::cout << "Decimal number: " << decimalNumber << std::endl;

We use the std::cout object to display the decimal number on the console.

1. Return 0:

return 0;

This statement ends the main function and returns 0 to indicate successful execution of the program.

By following these steps, you can convert a hexadecimal number into decimal in C++.