Addition for BigDecimal

Question

I want to do some simple sums with some currency values expressed in BigDecimal type.

BigDecimal test = new BigDecimal(0);
System.out.println(test);
test.add(new BigDecimal(30));
System.out.println(test);
test.add(new BigDecimal(45));
System.out.println(test);

Obviously I do not understand well the BigDecimal arithmetics, see output behind.

Test
0
0
0

Can anyone help me out?

Answer 1

BigInteger is immutable, you need to do this,

  BigInteger sum = test.add(new BigInteger(30));  
  System.out.println(sum);

Answer 2

BigDecimal test = new BigDecimal(0);
System.out.println(test);
test = test.add(new BigDecimal(30));
System.out.println(test);
test = test.add(new BigDecimal(45));
System.out.println(test);

Answer 3

The BigDecimal is immutable so you need to do this:

BigDecimal result = test.add(new BigDecimal(30));
System.out.println(result);

Answer 4

It looks like from the Java docs here that add returns a new BigDecimal:

BigDecimal test = new BigDecimal(0);
System.out.println(test);
test = test.add(new BigDecimal(30));
System.out.println(test);
test = test.add(new BigDecimal(45));
System.out.println(test);

Answer 5

It's actually rather easy. Just do this:

BigDecimal test = new BigDecimal(0);
System.out.println(test);
test = test.add(new BigDecimal(30));
System.out.println(test);
test = test.add(new BigDecimal(45));
System.out.println(test);

See also: BigDecimal.html#add(java.math.BigDecimal)