Thread: Need Help with Operators/ logic

Okay, I'm very, very new to java. I'm in an intro to computer science class and we got out first assignment to write a program. its from "An Into to Object Oriented Programming with java" by C. Thomas Wu.

all we have to do is create a program that calculate body mass index using the formula Bmi=Weight/(Height/100)^2 where weight is in kg and height is in cm.

Here is my code:

 
import javax.swing.*;
 
class Bmi
{
	public static void main(String[] args)
	{
		//*****
		// Declarations:
		//*****
 
		final double NUM1=100.0;	//The constant 100 in the formula
		String weightin;				//weight input
		String heightin;				//height input
		String description;			//if the output bmi is normal
		int weightp;					//weight primitive
		int heightp;					//height primitive
		double denom;					//height/NUM1
		double denommod;				//(height/NUM1)(height/NUM1)
		double bmi;						//final value-bmi
 
		heightin=JOptionPane.showInputDialog(null,"Please Enter your weight:\n (Kilograms)"); 						 //get weight
		weightin=JOptionPane.showInputDialog(null,"Thanks you. Now, Please enter your Height:\n (centimeters)"); //get height
 
		weightp=Integer.parseInt(weightin);		// convert height and weight to primitive values
		heightp=Integer.parseInt(heightin);
 
		denom=(heightp/NUM1);			//calulations
		denommod=(denom*denom);
		bmi=(weightp/denommod);
 
		if(bmi<=18.5);							//Understanding what the value means
			description="underweight";
		if((bmi>18.5)&(bmi<=25));
			description="normal";
		if((bmi>25)&(bmi<=30));
			description="overweight";
		if(bmi>30);
			description="obese";
 
		JOptionPane.showMessageDialog(null,"Your Body mass index is:" +bmi+ " \n This is considered " +description+".");
	}
}

I think the problem is in the middle chunk there with the operators labelled "calculations"
but it could be my data types?
my professor (who i think to be completely incompetent) told us to use these test parameters to start:
50 kg and 160 cm

i keep getting 640 with this program but the correct answer is roughly 19.5

if you could point out any convention errors, too, that would be great!
thanks!

I don't notice anything wrong. Your formula seems correct and there is nothing noticeably wrong syntactically.

Try debugging your code by printing out the values of all the variables used in your calculations to see where your formulas are going wrong.

how do i keep the program from delivering the bmi with more than just a few decimal places

Look at the DecimalFormat class for formatting doubles to desired formats.