Answer by Eric Postpischil for int and double divided by double java

2.3 is not exactly representable in IEEE-754 64-bit binary floating-point. What happens in your first code sequence is:

• The source text 2.3 is converted to the nearest representable value, 2.29999999999999982236431605997495353221893310546875.
• The exact mathematical result of multiplying that by 100000 is not exactly representable either, so it is rounded to 229999.99999999997089616954326629638671875.
• When this is converted to an int, the conversion truncates, producing 229999.
• Dividing that by 100000 rounds again, producing 2.29999000000000020094148567295633256435394287109375.
• When the above is printed, Java displays it as “2.29999”.