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Double number Rounding issue

de_britto
de_britto asked
on
Medium Priority
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Last Modified: 2010-04-01
Hi Experts,

Look at the simple example

double a = 1440.0;
double b = 0.06;
double c = a * b;

out.println("Result " + c)  gives 86.39999999999999;

Where
out.println("Result " + 1440.0 * 0.06) gives exact value 86.4   which is correct;

Does anybody knows why this happens, and how to fix a*b -> 86.4


Thanks
Britto
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student
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Mick BarryJava Developer
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DecimalFormat format = new DecimalFormat("#.#");
out.println(format.format(c));            
rrzstudent
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Commented:
to objects and mmuruganandam,  
Great, your solutions work for the given values, because DecimalFormat uses half-even rounding  for formatting.  

 "de britto" wanted the  exact value
>gives exact value 86.4   which is correct  

But what if the variables change ?  (  b = 0.061111 for example )  
How could your solution be applied to the general case ?  

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