Karel J Robot - Chapter 5 Programs: Repeating Instructions BACK TO KAREL MAIN
Instructions that Repeat
We will now learn how to make Karel perform repetitive tasks. In other words, we will learn how to make a command that can cause Karel to perform an action over and over. You will see that this saves many lines of code.
In computer science, the act of repeating a block of code is called a loop. There are two types loops we will use: the for loop and the while loop. See the examples below.
The FOR loop – a loop used when you want a robot to perform the same task a specific number of times.
Example 1: a for loop used to make exactly 5 moves:
public void move()
Example 2: a for loop used to make n moves:
public void move(int n)
The WHILE loop – a loop used when you want a robot to perform a task repeatedly until a condition becomes false (an unknown number of times).
Example 1: a while loop used to make a robot move to a wall an unknown distance away:
public void moveToWall()
Example 2: a while loop used to pick up an unknown number of beepers at its current location:
public void pickAllBeepers()