Capítulo 3 - Funções de usuário: Exemplo de criação e ativação

Summary

This tutorial demonstrates how to create a program to calculate the ideal weight of a person based on gender and height using custom functions. It explains the creation of the main function for input/output and a separate function for calculating the ideal weight using different formulas for men and women. The concept of memory scope is introduced, showing how variables in different functions exist in separate regions. The video also covers how the calculated weight is returned and displayed, along with key programming concepts such as function parameters, return values, and variable scope management.

Takeaways

• 😀 The program calculates the ideal weight of a person based on gender and height, using specific formulas for men and women.
• 😀 The formula for men's ideal weight is: 72.7 × height - 58, and for women: 62.1 × height - 44.7.
• 😀 The input data required are the gender (m or f) and the height of the person.
• 😀 The output data is the calculated ideal weight, displayed in the format 'Ideal weight = [value]'.
• 😀 The program is designed with two functions: the main function (Início) for input and output, and a specific function (CalcularPesoIdeal) for calculating the ideal weight.
• 😀 The function 'CalcularPesoIdeal' receives two parameters: gender and height, and returns the ideal weight as a real value.
• 😀 The main function (Início) will prompt the user for their gender and height before calling the 'CalcularPesoIdeal' function.
• 😀 The program's variables (gender, height, and ideal weight) are local to the functions they are declared in, ensuring they only exist in the scope of that function.
• 😀 The result of the calculation from the 'CalcularPesoIdeal' function is returned to the main function, where it is assigned to the variable 'peso ideal' for display.
• 😀 The key takeaway from the lesson is the distinction between local variables, function parameters, and how data flows between functions using the 'return' statement.

Q & A

What is the main objective of the program described in the script?

The main objective of the program is to calculate and display the ideal weight of a person based on their gender and height using two formulas: one for men and one for women.

What are the two formulas used to calculate the ideal weight for men and women?

For men, the formula is: 72.7 * height - 58. For women, the formula is: 62.1 * height - 44.7.

How does the program determine which formula to use for calculating the ideal weight?

The program uses the gender (sexo) entered by the user to determine which formula to apply. If the gender is 'm' for male, the male formula is used; if the gender is 'f' for female, the female formula is applied.

Why is the calculation of the ideal weight done in a separate function?

The calculation is done in a separate function to promote modularity and reusability. It also allows for better organization of code, where the main function handles user input and the separate function calculates the result.

What are the key components required to define the function `calcula_peso_ideal`?

The key components are: the function name (`calcula_peso_ideal`), the parameters (`sexo` for gender and `altura` for height), and the type of return value, which is the ideal weight (a real number).

What type of data does the program expect for the variables 'sexo' and 'altura'?

The 'sexo' variable expects a character ('m' for male, 'f' for female), while the 'altura' variable expects a real number representing the person's height in meters.

What happens when the user enters 'm' for gender and '1.75' for height in the program?

The program calculates the ideal weight for a male with the given height using the formula for men: 72.7 * 1.75 - 58, which results in 69.22. This value is then displayed as the ideal weight.

What is the significance of the `return` statement in the `calcula_peso_ideal` function?

The `return` statement sends the calculated ideal weight back to the calling function (`início`), allowing the result to be used outside of the `calcula_peso_ideal` function.

Why does the program use the `input()` function for gender and height?

The `input()` function is used to collect data from the user. It allows the user to enter their gender and height, which are necessary for calculating the ideal weight.

How does the concept of 'scope' apply to the variables in the program?

In the program, variables like `sexo`, `altura`, and `peso_ideal` are local to their respective functions. The variables in the `início` function are separate from those in the `calcula_peso_ideal` function, even if they have the same name. The scope determines where these variables are accessible within the program.