How can Karel check if it is in an even-numbered row?

To determine if Karel is in an even-numbered row, Karel should check its y-coordinate for evenness. In the Karel programming environment, the y-coordinate represents the row number, starting from zero. Rows are considered even if their y-coordinate (the number representing the row) is divisible by 2 without a remainder.

For example, Karel's position could be (3, 4), where the y-coordinate is 4; since 4 divided by 2 equals 2 with no remainder, it indicates that Karel is on an even row. By contrast, if Karel were on row 3 (where the y-coordinate is 3), it would not meet the condition of being even.

Checking the x-coordinate would not accurately determine the row's evenness, as it indicates the horizontal position rather than vertical. Evaluating against a predefined grid or counting steps taken does not directly provide information about the evenness of the row. Thus, using the y-coordinate is the most straightforward and reliable method to establish whether Karel is on an even row.