CODEWITHSUNDEEP
java
Will P.
Will P.

Reputation: 45

Decimal point control

I doing a program that will print out the sum and average of a set of numbers. I'm pretty new to java, and I can't seem to figure out how to get the .7 that is supposed to be on the end of the average, I only get .0. I don't think it has to do with my math, I think there is an error in my rounding statement. Could someone point the error out to me? Thanks guys.

    public class Program
  {
            public static void main (String[]args)
            {
                int a = 475;
                int b = 821;
                int c = 369;
                int d = 562;
                int e = a+b+c+d;
                double f = e/4;
                f=(int)(f*10+.5)/10;
                System.out.println("The sum of the four numbers is "+ e + "       and the average is "+ f);
            }

        }

Upvotes: 1

Views: 86

Answers (3)

user3437460
user3437460

Reputation: 17454

When you have an integer divide by another integer, this is call integer division. The output will the discard the decimal values.

For example:

double v1 = 5/2;  //Value of v1: 2.0 (0.5 discarded)
double v2 = 10/3; //Value of v2: 3.0 (0.333 discarded)

An integer division is happening in your codes at this line:

double f = e/4;

Hence, all the decimal values are discarded.

To retain the decimal value, you can simply do one the following (to indicate one of the operand is a decimal value, hence integer division will not occur):

double f = e/4.0;
double f = e/(double)4;
double f = e/4d;

Upvotes: 0

chenchuk
chenchuk

Reputation: 5742

You lost the decimal point because e/4 is an integer. try e/4F to indicate the expression as float number 

double f = e/4F;

Upvotes: 0

Manu
Manu

Reputation: 1485

Instead of double f = e/4;, do double f = e/4.0;

With e/4, you divide an int by an int, which results in an int. The result is afterwards assigned to a double. That's why you don't get decimals in your result.

With e/4.0, you divide an int by a double, which results in a double.

Upvotes: 3

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