BigDecimal and rounding

Question

I have been looking for answers here re: rounding and BigDecimal, but I am having trouble. Can someone help?

The actual result of the below division is 11.469...

        BigDecimal a = new BigDecimal(0.32);
        
        BigDecimal b = new BigDecimal(2.79);
        
        BigDecimal diffPercent = (a.divide(b, 2, RoundingMode.HALF_EVEN)).multiply(HUNDRED);  // 11.00
        BigDecimal diffPercent = (a.divide(b, 4, RoundingMode.HALF_EVEN)).multiply(HUNDRED);  // 11.4700

How can I get 11.47 (two decimal places)?

Using `.stripTrailingZeros()` would work fine – Nowhere Man Jun 27 '20 at 19:50 — Nowhere Man, Jun 27 '20 at 19:50

score 1 · Answer 1 · answered Jun 27 '20 at 19:39

BigDecimal bg = new BigDecimal("11.468");
MathContext mc = new MathContext(3); // 3 precision

// bg1 is rounded using mc
final BigDecimal round = bg.round(mc, RoundingMode.CEILING);
System.out.println(round);

Posting as this is another example of how to round

Joni · Accepted Answer · 2020-06-28T11:41:51.720

1

Instead of multiplying by BigDecimal(100), move the decimal point to the right:

BigDecimal diffPercent = (a.divide(b, 4, RoundingMode.HALF_EVEN)).movePointRight(2)

Output: 11.47

This works because moving the decimal point only adjusts the scale of the BigDecimal.

edited Jun 28 '20 at 11:41

answered Jun 27 '20 at 19:50

Joni

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BigDecimal and rounding

2 Answers2