How to Implement the main Function in C++

In this tutorial, we will explore how to implement the main function in C++ within the context of robotics. The main function is the entry point for every C++ program, and understanding its structure and execution is important for any robotics engineer.

Prerequisites

Directions

Open a terminal window, and type this:

cd ~/Documents/cpp_tutorial && code .

Create a new file, and save it as main_example.cpp. This will be our working file for this tutorial.

Type the following code into the editor:

#include <iostream>

int main(int argc, char *argv[]) {
    std::cout << "Welcome to Robotics Bootcamp!" << std::endl;

    // Print the command line arguments
    std::cout << "Arguments passed to the program:" << std::endl;
    for (int i = 0; i < argc; ++i) {
        std::cout << i << ": " << argv[i] << std::endl;
    }

    return 0;
}

In this code, we start by including the <iostream> library to handle input and output operations. 

Our main function here takes two parameters: argc and argv. 

  • argc is the count of command-line arguments passed to the program, including the program name
  • argv is an array of character strings representing those arguments.

This setup allows your robot’s software to accept various startup parameters that could control different modes of operation or testing procedures.

When you run this program, you’ll see the welcome message followed by the list of command-line arguments. 

1-main-example-no-arguments

Try running your program from a terminal with additional arguments to see how it captures and displays them.

g++ main_example.cpp -o main_example
./main_example
2-main-example-no-arguments

Try running it with some command line arguments.

./main_example arg1 "argument 2" test123
3-main-example-with-arguments

Thanks, and I’ll see you in the next tutorial. 

Keep building!

How to Use cout and endl in C++

In this tutorial, we will explore how to use cout and endl in C++ for outputting information in robotic projects. These elements are part of the iostream library and are essential for displaying messages and data in the console.

Prerequisites

Directions

Open a terminal window, and type this:

cd ~/Documents/cpp_tutorial && code .

Let’s create a new C++ file and name it robot_output.cpp.

Type the following code into the editor:

#include <iostream>

using namespace std;

int main() {
    string robot_status = "Active";
    int x_position = 10;
    int y_position = 20;

    cout << "Robot Status: " << robot_status << endl;
    cout << "Robot Position: (" << x_position << ", " << y_position << ")" << endl;

    cout << "Initializing robot..." << endl;
  
     // Simulating robot initialization
    cout << "Robot initialized successfully!" << endl;

    return 0;
}

In this code, we include the iostream header for input/output operations and use the using namespace std statement to bring the std namespace into the current scope.

Inside the main function, we declare variables for robot_status, x_position, and y_position, representing the status and position of the robot.

We use cout to output the robot’s status and position to the console.

 The << operator is used to concatenate strings and variables.

The endl manipulator is used to insert a newline character and flush the output buffer.

Next, we simulate the robot initialization process by outputting messages using cout and endl. 

Run the code.

1-robot-output

You should see the robot’s status, position, and initialization messages printed in the terminal.

That’s it. Thanks, and I’ll see you in the next tutorial.

Keep building!

How to Organize Your C++ Code with std Namespace

In this tutorial, we will explore how to use the std namespace in C++ for robotics. The std namespace helps organize your code and makes it more readable.

Prerequisites

Directions

Open a terminal window, and type this:

cd ~/Documents/cpp_tutorial && code .

Let’s create a new C++ file and name it simple_robot.cpp.

Type the following code into the editor:

#include <iostream>
#include <string>

using namespace std;

int main() {
    string robot_name = "AutomaticAddisonBot";
    int robot_battery = 80;

    cout << "Robot Name: " << robot_name << endl;
    cout << "Battery Level: " << robot_battery << "%" << endl;

    return 0;
}

In this code, we include the iostream and string headers for input/output operations and string manipulation, respectively.

We use the using namespace std; statement to bring the std namespace into the current scope, allowing us to use elements like cout, endl, and string without the std:: prefix.

Inside the main function, we declare variables for robot_name and robot_battery, representing the name and battery level of the robot.

We print the robot’s name and battery level using cout and endl without the std:: prefix since we are using the std namespace.

Run the code.

1-run-the-code

You should see the robot’s name and battery level printed in the terminal.

This example demonstrates how using the std namespace can make your code more concise and readable. 

Thanks, and I’ll see you in the next tutorial. 

Keep building!