Studi Kasus C++ 03 - Program Menghitung Berat Badan Ideal Menggunakan Bahasa Pemrograman C++

Introduction

In this tutorial, we will learn how to create a program in C++ that calculates ideal body weight. This guide is based on the principles discussed in the video "Studi Kasus C++ 03" by Jagat Koding. We will break down the logic behind the program and provide a step-by-step implementation to help you understand the coding process.

Step 1: Understand the Concept of Ideal Body Weight

Before diving into coding, it’s important to grasp the concept of ideal body weight. The ideal body weight can be calculated using various formulas, with one common method being:

• For men: Ideal Weight = 50 kg + 2.3 kg for each inch over 5 feet
• For women: Ideal Weight = 45.5 kg + 2.3 kg for each inch over 5 feet

Familiarize yourself with these formulas as they will be critical in our program.

Step 2: Set Up Your Development Environment

To write and test your C++ code, you need a suitable development environment. Follow these steps to set it up:

1. Download and install a C++ compiler, such as MinGW or use an IDE like Code::Blocks or Visual Studio.
2. Create a new project or file for your program.
3. Ensure your setup is ready by creating a simple "Hello, World!" program to test the environment.

Step 3: Write the Program Structure

Begin by writing the basic structure of your C++ program. Here’s how to do it:

1. Include the necessary headers:

   #include <iostream>
   using namespace std;
   

2. Define the main function:

   int main() {
       // Your code will go here
       return 0;
   }
   

Step 4: Input User Data

Next, we need to gather user data such as gender, height, and weight. Use the following code snippet to collect inputs:

char gender;
float height, idealWeight;

cout << "Enter gender (M/F): ";
cin >> gender;

cout << "Enter height in inches: ";
cin >> height;

Step 5: Calculate Ideal Body Weight

Now, based on the user input, implement the logic to calculate the ideal body weight. Use conditional statements to check the gender and apply the appropriate formula:

if (gender == 'M' || gender == 'm') {
    idealWeight = 50 + 2.3 * (height - 60);
} else if (gender == 'F' || gender == 'f') {
    idealWeight = 45.5 + 2.3 * (height - 60);
} else {
    cout << "Invalid gender input." << endl;
}

Step 6: Output the Result

Finally, display the calculated ideal body weight to the user. Add this code within the main function:

cout << "Your ideal body weight is: " << idealWeight << " kg" << endl;

Step 7: Complete Code Example

Here’s how the complete program looks:

#include <iostream>
using namespace std;

int main() {
    char gender;
    float height, idealWeight;

    cout << "Enter gender (M/F): ";
    cin >> gender;

    cout << "Enter height in inches: ";
    cin >> height;

    if (gender == 'M' || gender == 'm') {
        idealWeight = 50 + 2.3 * (height - 60);
    } else if (gender == 'F' || gender == 'f') {
        idealWeight = 45.5 + 2.3 * (height - 60);
    } else {
        cout << "Invalid gender input." << endl;
        return 1; // Exit the program with an error
    }

    cout << "Your ideal body weight is: " << idealWeight << " kg" << endl;
    return 0;
}

Conclusion

In this tutorial, you learned how to create a simple C++ program that calculates the ideal body weight based on user input. We covered everything from understanding the concept to writing and executing the code. For further learning, consider exploring more complex algorithms and C++ features such as functions and classes. Happy coding!