无法在 Groovy 中添加 BigDecimal 值

Question

def total = new BigDecimal("0.00");
total.add(new BigDecimal("1"));
println total;

考虑上面的以下代码：此代码的输出为零。

为什么？

Answer 1

您必须分配结果（请参阅下面的文档）。或得到 groovy:

def total = 0.0G + 1G
assert total.getClass() == BigDecimal
assert total==1.0G

total += 1.0G
assert total.getClass() == BigDecimal
assert total==2.0G

http://docs.oracle.com/javase/7/docs/api/java/math/BigDecimal.html#add%28java.math.BigDecimal%29

 public BigDecimal add(BigDecimal augend)

Returns a BigDecimal whose value is (this + augend), and whose scale is max(this.scale(), augend.scale()).

Parameters:

augend - value to be added to this BigDecimal.

Returns:

this + augend