Strings, StringBuffers, StringBuilders, Numbers, and BigNumbers - Java for COBOL Programmers - page 203

This is another example of how operator overloading could make Java applications
simpler to read and write. If Java had overloaded the math operators when applied
to BigNumber s, this syntax could be used:
customerBalanceYen = customerBalance * currencyValue;
instead of this syntax:
customerBalanceYen = customerBalance.multiply (currencyValue);
As it is, the math functions provided with the BigNumber classes are the only way to
add, subtract, multiply, and divide BigNumber s.

The BigDecimal constructors and math functions also support an optional
MathContext parameter. This class allows you to establish a particular set of Big-
Decimal attributes (scale, rounding mode) and use that set each time you need a
new BigDecimal .

MathContext currencyScale = new MathContext (123, RoundingMode.HALF_DOWN);
BigDecimal currencyValue = new BigDecimal (123, currencyScale);
BigDecimal currencyRate = new BigDecimal (1.3, currencyScale);
BigDecimal convertedCurrencyValue =
currencyValue.multiply (currencyRate, currencyScale);

Table 8.4 shows the most commonly used constructors for BigDecimal s and
BigInteger s.

TABLE 8.4 COMMON CONSTRUCTORS FOR BIGDECIMAL AND BIGINTEGER

Constructor Description COBOL Equivalent

BigDecimal Converts a BigInteger into a MOVE INTEGER1 TO

(BigInteger val) BigDecimal PACKED-NUM1

BigDecimal Converts a BigInteger into a MOVE INTEGER1 TO

(BigInteger BigDecimal with the scale requested PACKED-NUM1

unScaledVal, int scale)

BigDecimal Converts a double into a BigDecimal MOVE DOUBLE-NUM1 TO

(double val) PACKED-NUM1*

BigDecimal (String val) Converts a String representation of MOVE WITH CONVERSION

a number into a BigDecimal STRING1 TO PACKED-NUM1

continued