While Loops in Flogram

Introduction

While loops are another fundamental control structure in programming that allow you to repeat a block of code as long as a specified condition is true. In Flogram, while loops provide a way to create flexible and dynamic iterations, making it easier to solve problems that require repetition based on a condition.

Basic Syntax

The basic syntax of a while loop in Flogram is as follows:

while condition:
  # code to be executed while the condition is true

Here, condition is an expression that evaluates to a Boolean value (TRUE or FALSE). The code inside the loop will continue to execute as long as the condition remains TRUE.

Example: Guessing Game

Let’s create a simple guessing game using a while loop in Flogram:

fn guessingGame():
  secretNumber := 42
  mut guess := -1

  while guess != secretNumber:
  draw("Enter your guess:")
  guess := inputNumber()

  if guess < secretNumber:
    draw("Too low! Try again.")
  if guess > secretNumber:
    draw("Too high! Try again.")

  draw("Congratulations! You guessed the secret number.")

In this example, the while loop continues to prompt the user for a guess until the guess matches the secretNumber. The inputNumber() function (assumed to be defined elsewhere) reads the user’s input as a number. The loop provides feedback to the user, indicating whether their guess is too low or too high.

Example: File Processing

Another common use case for while loops is processing files. Here’s an example that reads lines from a file until the end of the file is reached:

fn processFile(filePath: String):
  file := open(filePath, "r")
  mut line := ""

  while (line := file.readLine()) != "":
    # Process each line
    draw("Processing line: {line}")

  file.close()
  draw("File processing complete.")

In this example, the while loop reads lines from the file using the readLine() method (assumed to be defined for the file object). The loop continues until readLine() returns an empty string, indicating the end of the file. Inside the loop, each line is processed as needed.

Best Practices

When using while loops in Flogram, consider the following best practices:

• Prefer foreach loops over for loops over while loops for performance and safety
• Ensure that the loop condition eventually becomes FALSE to avoid infinite loops.
• Use meaningful variable names for the loop condition and any variables used within the loop.
• Keep the loop body focused and concise, performing a single task or related set of tasks.
• Consider using a break statement to exit the loop early if a certain condition is met.

Conclusion

While loops in Flogram provide a powerful way to create dynamic iterations based on a condition. By understanding the basic syntax and seeing practical examples, you can effectively use while loops to solve problems that require repetition.