Format of BigDecimal number

Question

BigDecimal val = BigDecimal.valueOf(0.20);
System.out.println(a);

I want to store in val a value 0.20 and not 0.2. What I

Answer 1

You're passing a double to BigDecimal.valueOf(). And 0.20 is exactly the same double as 0.2. Pass it a String, and the result will be different, because the scale of the BigDecimal will be deduced from the number of decimals in the String:

BigDecimal bd1 = new BigDecimal("0.20");
BigDecimal bd2 = new BigDecimal("0.2");

System.out.println(bd1.toPlainString() + ", scale = " + bd1.scale()); // 0.20, scale = 2
System.out.println(bd2.toPlainString() + ", scale = " + bd2.scale()); // 0.2, scale = 1

NumberFormat nf = NumberFormat.getInstance();

nf.setMinimumFractionDigits(bd1.scale());
System.out.println(nf.format(bd1)); // 0,20 (in French locale)

nf.setMinimumFractionDigits(bd2.scale());
System.out.println(nf.format(bd2)); // 0,2 (in French locale)