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Preserving the Precision Value of a double

Submitted by Ramnath on Mon, 11/15/2010 - 03:56

Java

I have a double variable

double d = 4.24

When i convert this into a String I lose the precision Value and it returns back 4.2.

I know we could achieve this using Decimal format .... but is there any other way of achieving this.

2 answers

Re: Preserving the Precision Value of a double

Mon, 11/15/2010 - 20:01 — Sameera

I do not think loss of precision should happen for only 2 decimals. A quick program shows that it works perfectly.

double d = 2.34;
String str = String.valueOf(d);
System.out.println(str);
double d1 = Double.parseDouble(str);
System.out.println(d1);

will print
2.34
2.34

How are you converting double to String and back?
In addition, if you are looking for precise decimal values, you should use BigDecimal instead of double.

Re: Preserving the Precision Value of a double

Wed, 11/17/2010 - 03:46 — Ramnath

thank you for the code , but if I get a double d = 2.30 then System.out.println(str); --> would be 2.3 and "0" would be lost. I do agree your thoughts for using Big Decimal , but as i was maitaining Legacy Code , it was not possible at this juncture.