Problem with DIVISION

[Ramandeep]

I've written the following simple program to display a pecentage for each Pizza Chains total units but the percentage is comming out as 00.00 for all of the answers why is this? I bet it's going to be a simple mistake I made. Every thing works fine but it's to do with the division that produces the zeros any ideas?

import java.text.DecimalFormat;

class pizzaChains
{
    public static void main ( String args[] )
    {
	DecimalFormat twoDP = new DecimalFormat( "00.00" );
	
	String chains[] = new String[10];
	int units[] = new int[10];
	
	int totalUnits = 0;
	
	// initialise chains array with pizza chains name's
	chains[0] = "Pizza Hut       ";
	chains[1] = "Domino's        ";
	chains[2] = "Little Caesar's ";
	chains[3] = "Papa John's     ";
	chains[4] = "Round Table     ";
	chains[5] = "Godfather's     ";
	chains[6] = "Chuck E. Cheese ";
	chains[7] = "Picadilly Circus";
	chains[8] = "Pizza Inn       ";
	chains[9] = "Pizza Kitchen   ";
	
	// initialise units arrays with units for each pizza chain
	units[0] = 14400;
	units[1] = 5950;
	units[2] = 4300;
	units[3] = 1517;
	units[4] = 539;
	units[5] = 554;
	units[6] = 312;
	units[7] = 680;
	units[8] = 514;
	units[9] = 80;
	
	// calculate total units for all pizza chains
	for ( int i = 0; i <= 9; i++ )
	    totalUnits = totalUnits + units[i];
	
	// calculate & display total percentage of units for each pizza chain
	System.out.println ( "-----------------------------------" );
	System.out.println ( "PIZZA CHAINS    \tTOTAL UNITS" );
	System.out.println ( "-----------------------------------" );
	
	for ( int i = 0; i <= 9; i++ )
	    System.out.println ( chains[i] + "\t" + twoDP.format ( ( units[i] / totalUnits ) * 100 ) + "%" );
	
	System.out.println ( "-----------------------------------" );
    }   
}

>>> THANKS IN ADVANCE <<<

[Dillinger4]

just switch the units[i] / totalUnits to totalUnits / units[i]

[Ramandeep]

Thanks for your post Dilenger4 but that would produce the wrong result, as that isn't how a percentage is worked out. I gave it a go any way and it did produce the incoreect results.

Any Ideas Anyone???

[Dillinger4]

Looking at the output. The way you had it is probably the right
way. But looking through some of my books there seems to be two format methods:

public StringBuffer format( long number, StringBuffer result, FieldPosition fieldposition);

public StringBuffer format(double number, StringBuffer result, FieldPosition fieldposition);

bolth return a stringbuffer.

[Dillinger4]

I fiddled around with it and i think this would be the correct output. Tell me what you think.

import java.text.DecimalFormat;

class pizzaChains
{
public static void main ( String args[] )
{
//DecimalFormat twoDP = new DecimalFormat("00.00");

String chains[] = new String[10];
double units[] = new double[10];
double per;
double tu = 0.0;

// initialise chains array with pizza chains name's
chains[0] = "Pizza Hut ";
chains[1] = "Domino's ";
chains[2] = "Little Caesar's ";
chains[3] = "Papa John's ";
chains[4] = "Round Table ";
chains[5] = "Godfather's ";
chains[6] = "Chuck E. Cheese ";
chains[7] = "Picadilly Circus";
chains[8] = "Pizza Inn ";
chains[9] = "Pizza Kitchen ";

// initialise units arrays with units for each pizza chain
units[0] = 14400;
units[1] = 5950;
units[2] = 4300;
units[3] = 1517;
units[4] = 539;
units[5] = 554;
units[6] = 312;
units[7] = 680;
units[8] = 514;
units[9] = 80;

// calculate total units for all pizza chains

for ( int i = 0; i <= 9; i++ ){
tu += units[i];
}

// calculate & display total percentage of units for each pizza chain
System.out.println ( "-----------------------------------" );
System.out.println ( "PIZZA CHAINS \tTOTAL UNITS" );
System.out.println ( "-----------------------------------" );

for ( int i = 0; i <= 9; i++ ){
per = tu / units[i];
Double d = new Double(per);
String s = d.toString();
int pos = s.indexOf(".");
String sub = s.substring(0, pos + 2);
System.out.println ( chains[i] + "\t" + sub + "%" );
}
System.out.println("---------------------------------");
}

}

[Dillinger4]

if you ommit or comment out these following lines:

// Double d = new Double(per);
// String s = d.toString();
// int pos = s.indexOf(".");
// String sub = s.substring(0, pos + 2);

and are left with this:


for ( int i = 0; i <= 9; i++ ){
per = tu / units[i];
System.out.println ( chains[i] + "\t" + per + "%" )
}
System.out.println("---------------------------------");
}

you will end up getting:

Pizza Hut 2.00319444444444445%
Domino's 4.848067226890756%

ect.... ect......
searching a string for the "." to obtain a sub string
was the only way i could figure out how to format the output to get the right amount of decimal places.

[VirtuallyVB]

int i=1, j=3;
(i/j == 0) not 0.3333etc.
Try "float" for totalUnits and units[].

Dilenger4,
I think he's calling the inherited method
public final String format(double number)
from java.text.NumberFormat
and I just noticed that you metioned integer versus floating point division.

[Ramandeep]

Thanks guys!!! I changed totalUnits to float and it works, yehhhhhhh

!!! THANKS ONCE AGAIN !!!