How to add up many BigDecimals in Java

Question

I have this program in which I need to add up many BigDecimals. I have the following snippet of code

BigDecimal Average = new BigDecimal(3.0);
BigDecimal ATT = new BigDecimal(0.0);
ATT.add(A_BigDecimal);
ATT.add(B_BigDecimal);
ATT.add(C_FullBigDecimal);
System.out.println("Total Amount: " + ATT); 
System.out.println("Average: " + ATT.divide(Average));

I keep getting errors everytime I try variants of this code, how do you add many BigDecimals together? Edit: Forgot to mention that the output is zero, always zero, as if the reference variable isnt reading the add function.

@Steve for some reason the output is zero, I am really stuck — Dcdw51, Oct 30 '16 at 21:01
You should provide a reproducible example. `A_BigDecimal`, `B_BigDecimal` and `C_FullBigDecimal` are used but not defined anywhere. — Steve, Oct 30 '16 at 21:09
Did you *read* the javadoc of [`add(BigDecimal augend)`](https://docs.oracle.com/javase/8/docs/api/java/math/BigDecimal.html#add-java.math.BigDecimal-)? ***Returns** a BigDecimal whose value is (this + augend)* Or the javadoc of [`BigDecimal`](https://docs.oracle.com/javase/8/docs/api/java/math/BigDecimal.html) itself? ***Immutable**, arbitrary-precision signed decimal numbers.* — Andreas, Oct 30 '16 at 21:53

score 3 · Answer 1 · answered Oct 30 '16 at 21:08

3

BigDecimal is immutable. Once the object is created, it cannot be changed.

The add method will return the result of the calculation. You will probably want to assign that return value to something.

answered Oct 30 '16 at 21:08

Joe C

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score 1 · Answer 2 · answered Oct 30 '16 at 21:19

This is what Joe C meant in updated code:

BigDecimal Average = new BigDecimal(3.0);
BigDecimal ATT = new BigDecimal(0.0);
ATT = ATT.add(A_BigDecimal);
ATT = ATT.add(B_BigDecimal);
ATT = ATT.add(C_FullBigDecimal);
System.out.println("Total Amount: " + ATT); 
System.out.println("Average: " + ATT.divide(Average));

How to add up many BigDecimals in Java

2 Answers2