Answer:

Some Machines that Use Cycles

Bicycle — your legs drive the pedals connected to a gear which spins.
CD Player — the disk spins (cycles) as the laser moves across it.
TV Set — pictures are put one the screen one after another as long as the set is on.
Water Pump — often a piston repeatedly moves in and out of a cylinder.
Laundry Dryer — rotating drum.
Clock — shows the same times every day. If the clock is mechanical, its insides are gears and springs with many mechanical cycles. If the clock is electronic the cycles are still there, but harder to see.
Sun and the Earth — endlessly cycling, seasons flowing one into the next.

Perhaps the ultimate example of the usefulness of cycles is the ultimate machine — the wheel.

The `while` statement

Here is a program with a loop:


// Example of a while loop
class LoopExample
{
  public static void main (String[] args ) 
  {
    int count = 1;          // start count out at one
    while ( count <= 3 )    // loop while count is <= 3
    {
      System.out.println( "count is:" + count );
      count = count + 1;    // add one to count
    }
    System.out.println( "Done with the loop" );
  }
}

The flowchart shows how the program works. First, count is set to one. Then it is tested to see if it is less than or equal to three.

If the test returns true the two statements in the block following the while are executed. The statement count = count + 1 increases the value stored in the variable count by adding one to it. Then execution goes back to the while statement and the process is repeated.

If the test returns false, execution goes to the "Done with loop" statment. Then the program ends.

Copy this program to a file and run it. Then hack upon it. See if changing a few things does what you expect.

Answer:

Some Machines that Use Cycles

The while statement

QUESTION 2:

The `while` statement