What does the 'start' function do in the Diagonal program?

The 'start' function in the Diagonal program is specifically designed to lay a diagonal row of tennis balls. This is an important feature in programming because it demonstrates Karel's ability to navigate the grid and place objects in a specific arrangement.

When Karel executes the 'start' function, it follows the instructions to move step by step diagonally, placing a tennis ball at each point on its path. This reinforces concepts such as movement control, spatial awareness, and the execution of commands in a sequential manner.

The focus on creating a diagonal line highlights Karel's efficiency in carrying out programmed actions and the capability to manipulate its environment systematically. Moreover, understanding this function within the context of the overall program helps learners appreciate how these structured commands come together to achieve a visual outcome.