Question

In the following code, what would be a good Postcondition to write?

/*Precondition:Karel is on a spot with a tennis ball facing East
/*Postcondition:...
function getOnTop(){
turnLeft();
move();
turnRight();
}

Answer 1

The appropriate postcondition for the code provided is that Karel is one spot North of the starting position with the tennis ball and is facing East. This postcondition details Karel's expected state after executing the 'getOnTop()' function.

Step-by-step explanation:

The student asked about the appropriate postcondition for the given code snippet involving Karel, a robot from a programming environment used to teach coding concepts. In the context of the provided code, the precondition mentions that Karel starts on a spot with a tennis ball facing East. The code 'getOnTop()' instructs Karel to turn left, move one spot, and then turn right. Based on the actions taken by Karel, a good postcondition would describe the expected state of Karel after the function has been executed.

A suitable postcondition would be:

• Karel is one spot North of the original spot with a tennis ball.
• Karel is facing East.

This postcondition provides a clear explanation of Karel's expected position and orientation after the 'getOnTop()' function is completed, which is essential for understanding the outcome of the function and is crucial for debugging and further programming steps.