Thread: Rounding with printf

import java.util.Scanner;
 
public class BouncingBall
{
  public static void main(String[] args)
  {
    Scanner keyboard = new Scanner(System.in);
    int bounce = 0, time = 0;
    double height = 0.0;
    double velocity = 0;
 
    System.out.println("Enter the initial velocity of the ball: ");
    velocity = keyboard.nextDouble();
 
    do
    {
      System.out.print("Time: % Height: 1.1f",
                               time, height);
      time ++;
 
      height += velocity;
      velocity -= 32;
 
      if (height < 0)
      {
        height *= -0.5;
        velocity *= -0.5;
        bounce++;
 
        System.out.println("Bounce!");
      }
    } while (bounce < 5);
  }
}

I need all height values in this program to be rounded to the nearest 0.1. The part after printf is what I wrote down from what my professor said to do. However, the program is not running properly. The program does run properly when I do this instead:

System.out.println("Time: " + time + " Height: " + height);
      time ++;

However, the Height values don't get rounded to the nearest 0.1. How to I make it so the program rounds the height values to the nearest 0.1 using printf?

I think your note taking wasn't so good. And you say there's a printf() statement in the code you posted, but I see a print(). Try playing with the following instead:

    do
    {
      System.out.printf("Time: %d Height: %1.1f\n",
                               time, height);