Mathematical operations in Java

This section looks at how to perform various types of calculation in Java. Depending on your needs, there are essentially two "frameworks" for doing calculations:

• for most "everyday" calculations, Java's built-in primitive types provide the fastest, simplest solution: operations on ints, longs, floats, doubles are straightforward to program and generally map directly on to low-level processor instructions, allowing most to complete in the order of a nanosecond with any stored numbers taking up a few bytes of memory;
• for special cases, the BigInteger and BigDecimal classes allow decimal numbers with an arbitrary number of digits to be stored and calculated on, up to the limits of available memory; the time and memory requirements then depend more heavily on the operation being performed and the number of digits involved, and the code involved can be a little clumsier.

Calculations with primitive types

On the next and subsequent pages, we look at floating point primitive operations in Java: that is, operations on the float and double data types.

Calculations with BigInteger and BigDecimal

For more specialist applications, we later look at the BigInteger and BigDecimal classes, which allow representation of— and calculations on— numbers with an arbitrary number of digits. We include a look at the performance of BigInteger/BigDecimal operations, in particular an analysis of the performance of multiplication.

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