Thread: issues with a float

Hi there,

I have decided to learn java programming, rather than working though a book which i find very dull i have just dived in by writing (trying to write) an application.

my application is for my other passion in life darts. so basically what the application does at the moment is calculates a players score from 501 down to 0 finishing on a double. this works fine but when i try to calculate the players 1 dart average i'm getting the wrong figure. To test this I did a 9 dart leg and the 1 dart average should be 55.67 however my code comes up with 55.0

I know that i'm probably missing something really obvious, i'm just at a loss to know what it is?

here is the code, appologies if anyone thinks its messy, it's the first programming i have done for about 14 years!

import java.util.Scanner;
 
public class DartApp {
	public static void main(String[] args){
		//create a scanner
		Scanner scanner = new Scanner(System.in);
 
		int total = 501;	//to be changed depending on game
		int nthrows = 0;	//number of throws to work out average
		float tdartave;		//three dart average calculator
 
		do{		
			System.out.print("enter player 1 score: ");
			int score = scanner.nextInt();
 
			total = total - score;
			System.out.println("score is " +total);
 
			//calculate number of throws
			if (total>0){
				nthrows = nthrows +3;}
			else{
				System.out.print("which dart was the winning dart 1,2,3 : ");
				int wdart = scanner.nextInt();
				nthrows = nthrows + wdart;
				System.out.println("darts thrown = " +nthrows);}
		}while (total>0);
 
		tdartave = (501 / nthrows);
		System.out.println("three dart average = " +tdartave);
 
	}
}

cheers for any help that can be offered, and sorry if I appear thick
Mike

You're probably having an issue with integer arithmetic. If variables in an expression are int, the compiler does int arithmethic. For example: 9/5 = 1 or 4/5 = 0
Use floating point numbers in the expression for the compiler to evaluate an expression as float.
1.0/2 = 0.5
or
(float)1 / 2

501.0 is a double. Your code reduces its precision to a float.
There really is no reason to use a float.
Change your variable to a double.
Or make the number a float by adding a trailing f : 501.0f

cheers for the replies
by changing to

tdartave = 501.0f / nthrows;

I get the result 55.666668 which is perfect for the time being, having it rounding down to 55 the three dart average was out by 2.

I know the calculation was for a one dart average, but i was trying to find where the 2 points had gone