> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/NormandoRamirezDelgado/6C-Febrero-2026/llms.txt
> Use this file to discover all available pages before exploring further.

# Grade Calculator

> Build a grade calculation system with functions and lists

## Exercise Overview

In this exercise, you'll learn how to create a comprehensive grade management system that:

* Captures student grades from user input
* Calculates averages
* Identifies grades above the average
* Detects failing grades
* Manages multiple lists (movies, colors, etc.)

## Exercise 1: Grade Analysis System

### Problem Statement

Create a program that:

<Steps>
  <Step title="Capture 5 grades">
    Ask the user to input 5 grades (decimal numbers)
  </Step>

  <Step title="Calculate average">
    Compute the average of all grades
  </Step>

  <Step title="Find grades above average">
    Display all grades that are greater than or equal to the average
  </Step>

  <Step title="Identify failing grades">
    Display all grades below 6.0 (failing grades)
  </Step>
</Steps>

### Solution Components

#### Function 1: Capture Grades

```dart theme={null}
import 'dart:io';

List<double> capturarCalificaciones(List<double> calificaciones) {
  for (var i = 0; i < 5; i++) {
    print('Introducir un Valor doble:');
    calificaciones.add(double.parse(stdin.readLineSync()!));
  }
  return calificaciones;
}
```

<Note>
  This function uses `double.parse()` to convert string input to decimal numbers, allowing for grades like 8.5 or 9.75.
</Note>

#### Function 2: Calculate Average

```dart theme={null}
double calcularPromedio(List<double> calificaciones) {
  double suma = 0.0;
  for (var calificacion in calificaciones) {
    suma += calificacion;
  }
  return suma / calificaciones.length;
}
```

<Accordion title="Understanding the average calculation">
  The function:

  1. Initializes a sum variable to 0.0
  2. Iterates through all grades, adding each to the sum
  3. Divides the sum by the total number of grades
  4. Returns the result as a double
</Accordion>

#### Function 3: Display Grades Above Average

```dart theme={null}
void imprimirMayoresPromedio(List<double> calificaciones, double promedio){
  for (var calificacion in calificaciones) {
    if (calificacion >= promedio) {
      print('La calificacion $calificacion es mayor o igual al Promedio');
    }
  }
}
```

#### Function 4: Display Failing Grades

```dart theme={null}
void imprimirReprobatorias(List<double> calificaciones){
  for (var calificacion in calificaciones) {
    if (calificacion < 6.0) {
      print('La calificacion $calificacion es Reprobatoria');
    }
  }
}
```

<Warning>
  In this system, any grade below 6.0 is considered failing. Make sure to adjust this threshold based on your grading system.
</Warning>

### Complete Program

```dart theme={null}
import 'dart:io';

List<double> capturarCalificaciones(List<double> calificaciones) {
  for (var i = 0; i < 5; i++) {
    print('Introducir un Valor doble:');
    calificaciones.add(double.parse(stdin.readLineSync()!));
  }
  return calificaciones;
}

double calcularPromedio(List<double> calificaciones) {
  double suma = 0.0;
  for (var calificacion in calificaciones) {
    suma += calificacion;
  }
  return suma / calificaciones.length;
}

void imprimirMayoresPromedio(List<double> calificaciones, double promedio){
  for (var calificacion in calificaciones) {
    if (calificacion >= promedio) {
      print('La calificacion $calificacion es mayor o igual al Promedio');
    }
  }
}

void imprimirReprobatorias(List<double> calificaciones){
  for (var calificacion in calificaciones) {
    if (calificacion < 6.0) {
      print('La calificacion $calificacion es Reprobatoria');
    }
  }
}

void main() {
  List<double> calificaciones = [];
  capturarCalificaciones(calificaciones);
  double promedio = calcularPromedio(calificaciones);
  imprimirMayoresPromedio(calificaciones, promedio);
  imprimirReprobatorias(calificaciones);
}
```

## Exercise 2: Multiple List Management

### Problem Statement

Create a program that manages two lists (movies and colors) and:

<Steps>
  <Step title="Load initial data">
    Collect 5 items for each list from the user
  </Step>

  <Step title="Add more data">
    Add one more item to each list
  </Step>

  <Step title="Display lists">
    Print all items in a numbered format
  </Step>

  <Step title="Show list sizes">
    Display the total count of items in each list
  </Step>
</Steps>

### Solution Components

#### Reusable Function: Load List

```dart theme={null}
import 'dart:io';

void cargarLista(List<String> lista, String mensaje){
  for (var i = 0; i < 5; i++) {
    print('Introducir tu $mensaje:');
    lista.add(stdin.readLineSync()!);
  }
}
```

<Tip>
  By accepting a `mensaje` parameter, this function can be reused for any type of list, making the code more maintainable.
</Tip>

#### Reusable Function: Add Data

```dart theme={null}
List<String> agregarDatos(List<String> lista, String mensaje) {
  print('\nAgregar $mensaje:');
  lista.add(stdin.readLineSync()!);
  return lista;
}
```

#### Reusable Function: Print Lists

```dart theme={null}
void imprimirListas(List<String> lista, String mensaje) {
  print('\nListado de $mensaje:');
  for (var i = 0; i < lista.length; i++) {
    print('${i + 1} - ${lista[i]}');
  }
}
```

<Note>
  The list is printed with 1-based numbering (`i + 1`) to make it more user-friendly, even though list indices start at 0.
</Note>

#### Reusable Function: Display Size

```dart theme={null}
void tamanioListas(List<String> lista, String mensaje) {
  print('\nEl tamaño de la lista de $mensaje es: ${lista.length}');
}
```

### Complete Program

```dart theme={null}
import 'dart:io';

void cargarLista(List<String> lista, String mensaje){
  for (var i = 0; i < 5; i++) {
    print('Introducir tu $mensaje:');
    lista.add(stdin.readLineSync()!);
  }
}

List<String> agregarDatos(List<String> lista, String mensaje) {
  print('\nAgregar $mensaje:');
  lista.add(stdin.readLineSync()!);
  return lista;
}

void imprimirListas(List<String> lista, String mensaje) {
  print('\nListado de $mensaje:');
  for (var i = 0; i < lista.length; i++) {
    print('${i + 1} - ${lista[i]}');
  }
}

void tamanioListas(List<String> lista, String mensaje) {
  print('\nEl tamaño de la lista de $mensaje es: ${lista.length}');
}

void main() {
  List<String> peliculas = [];
  List<String> colores = [];

  //Cargamos 5 datos en cada Lista
  cargarLista(peliculas, 'Pelicula');
  print('');
  cargarLista(colores, 'Color');

  //Añadir 1 elemento más a cada lista
  agregarDatos(peliculas, 'una Pelicula');
  agregarDatos(colores, 'un Color');

  //Imprimimos los elementos de lista de manera enumerada
  imprimirListas(peliculas, 'Peliculas');
  imprimirListas(colores, 'Colores');

  //Imprimir el Tamaño de cada Lista
  tamanioListas(peliculas, 'Peliculas');
  tamanioListas(colores, 'Colores');
}
```

## Key Concepts

<CardGroup cols={2}>
  <Card title="List<double>" icon="decimal">
    Used for storing decimal numbers like grades
  </Card>

  <Card title="List<String>" icon="text">
    Used for storing text like movie names or colors
  </Card>

  <Card title="Reusable Functions" icon="recycle">
    Functions with parameters can work with different data
  </Card>

  <Card title="Data Validation" icon="check">
    Important to check for failing grades and other conditions
  </Card>
</CardGroup>

## Practice Challenges

<AccordionGroup>
  <Accordion title="Challenge 1: Enhanced Statistics">
    Add functions to find:

    * Highest grade
    * Lowest grade
    * Number of passing grades
    * Percentage of students passing
  </Accordion>

  <Accordion title="Challenge 2: Grade Categories">
    Categorize grades into:

    * Excellent (9.0-10.0)
    * Good (8.0-8.9)
    * Satisfactory (7.0-7.9)
    * Passing (6.0-6.9)
    * Failing (below 6.0)
  </Accordion>

  <Accordion title="Challenge 3: Combined Lists">
    Modify the movie/color program to:

    * Allow the user to choose how many items to add initially
    * Add a search function to find specific items
    * Sort the lists alphabetically
    * Remove items by index
  </Accordion>
</AccordionGroup>

## Best Practices

<CardGroup cols={2}>
  <Card title="Separation of Concerns" icon="layer-group">
    Each function should do one thing well
  </Card>

  <Card title="Meaningful Names" icon="tag">
    Use descriptive function and variable names
  </Card>

  <Card title="Input Validation" icon="shield-check">
    Always validate user input to prevent crashes
  </Card>

  <Card title="Code Reusability" icon="arrows-rotate">
    Write functions that can be used in different contexts
  </Card>
</CardGroup>