Adding the elements of a BigDecimal Array in java

Question

I am new to Java and I came up to this error in my program where I can't add the elements in an array of BigDecimal elements. I successfully made it with Integer and Double types but when I change the type to BigDecimal, it won't work at all.

import java.math.*;
import java.util.*;
public class AddBigRealNumbers {

public static void main(String[] args) {
    try{

        Scanner von = new Scanner(System.in);
        System.out.println("Enter the number of figures to be added:");
        int numfig;
        numfig = von.nextInt();
        BigDecimal []nums = new BigDecimal[numfig];

        System.out.println("Enter the elements:");

        for(int i=0; i<numfig;i++){
            nums[i]=von.nextBigDecimal();
        }
        System.out.println("The elements are: ");
        for(int i=0; i<numfig;i++){
            System.out.println(nums[i]);
        }
        BigDecimal sum=BigDecimal.ZERO;
        for (BigDecimal i : nums)
            sum += i;
        System.out.println("The sume of these numbers is:"+sum);



    }
    catch(Exception e){
        System.out.println("Your exception is:" +e);
    }

}

}

Define "doesn't work at all". Does it not compile? If so, what error do you get? Does it throw an exception while running? Does it run but not produce the correct output? — Oblivious Sage, Mar 10 '15 at 13:05
Actually, it is just on the adding portion, but the others will still work. — Rachel Anne Daquis, Mar 10 '15 at 15:28

score 3 · Accepted Answer · answered Mar 10 '15 at 12:57

3

You can't add BigDecimal with +, you have to use its add() function. It is also immutable, so using the same BigDecimal sum for the whole addition won't work.

BigDecimal isn't just another class for numbers like Integer and Double are.

answered Mar 10 '15 at 12:57

LisaMM

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bwegs · Answer 2 · 2015-03-10T13:20:05.610

1

Because BigDecimal is immutable as LisaMM pointed out, you will need to increment your sum like so:

for (BigDecimal i : nums) {
        sum = sum.add(i);
}

...

sum.add(i);  <-- this wont't work

Instead we need to reassign a new BigDecimal to sum using its current value incremented by i.

edited Mar 10 '15 at 13:20

answered Mar 10 '15 at 13:14

bwegs

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score 0 · Answer 3 · edited Jul 30 '15 at 00:27

0

BigDecimal sum = null;
for (int i = 0; i < lengthOfArray; i++) {
    if (sum == null) {
        sum = data[i];
    } else {
        sum = sum.add(data[i]);
    }
}

edited Jul 30 '15 at 00:27

Nathan Tuggy

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answered Jul 29 '15 at 22:42

Mayur

1

Adding the elements of a BigDecimal Array in java

3 Answers3