This pattern is one of the most important ones in all of programming. X = x + 1

Question

It is used to increase the value of a variable by 1. You might call it the counter pattern since it can be used to make a variable that counts up. You'll use this pattern a lot, especially with the draw loop. Let's see what that looks like.

Do This

This program creates a variable counter and then uses the counter pattern to make it count up. When you run the program what do you think you'll see on the screen?

Run the program to check your prediction.

Read the program and make a prediction of what the output will be.

Discuss with a neighbor. Can you explain what you observed?

Answer 1

Based on your description, the program is implementing a simple counting mechanism using the counter pattern X = X + 1, where X is the variable counter.

Prediction:

When the program is run, I expect to see the value of counter start at 0 and then incrementally increase by 1 in each iteration of the draw loop. Depending on the duration for which the program runs, I might see a series of numbers displaying on the screen in increasing order, such as:

0
1
2
3
4
...
n

Where n is the final value of the counter when the loop stops or the program is interrupted.

Explanation of Observed Behavior:

Upon running the program, if it behaves as predicted, I would see an output sequence of numbers that begins at 0 and continues to increment. The screen may refresh on each iteration, displaying the updated value of the counter, which visually represents how the variable is modifying its value over time.

I could discuss this with a neighbor by explaining that the counter pattern is a foundational concept in programming, often used for loops, counting occurrences, or tracking elapsed time. The continuing increase of the counter reflects the iteration of the draw loop, which is likely repeatedly executing a portion of code that updates the counter variable. This demonstrates how variables can change dynamically during program execution.