How can I verify how many decimals a number has in Java?
I need to calculate PI to a certain number of decimal, and I want to know how I can stop my loop when I reach the desired decimals number?
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You can format the PI output for required decimals – Abimaran Kugathasan Mar 01 '14 at 10:52
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1You probably use `BigDecimal` for the calculation, which has a `scale()` method to return the number of decimals of the number. So, for 3.1415 `scale()` would yield 4. Perhaps you can use it in your algorithm. – Daniël Knippers Mar 01 '14 at 11:03
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You can't check the number of decimals on a double directly, but you can convert it to a String using String str = number + ""; and then check str.length.
Warlord
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It's probably not going to help solve the actual problem, but totally the correct answer to the question. – Ted Bigham Mar 01 '14 at 11:13
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If you use BigDecimal for your calculation you could set the scale to the desired value.
nitnamby
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If you only need a small precision e.g. 15 decimal places, you can use double for that. To specify the number of digits you could use Math.pow(10, -decimalPlaces) to calculate the smallest allowed deviation.
SpiderPig
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1) you firstly convert it to string
2)Then take a substring from '.' to end
3) Thenget the length of this substring
TruePS
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