How do we round only if the number is 10.0
Ex 10.0...
# mathematicsz
zain
10/26/2021, 10:11 AMHow do we round only if the number is 10.0
Ex 10.0 = 10
10.3 = 10.3
10.7 = 10. 7
Is there any easier way
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altavir
10/26/2021, 11:07 AMWhat output type do you want to have?
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zain
10/26/2021, 11:15 AMDouble
zain
10/26/2021, 11:15 AMSorry String
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altavir
10/26/2021, 11:19 AMThen maybe
num.toString().replace(".0", "")❤️ 2
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zain
10/26/2021, 11:27 AMOh yes this works!
zain
10/26/2021, 11:27 AMThank you
zain
10/26/2021, 11:33 AM10.04 Cases in which this fails 🤔
zain
10/26/2021, 11:34 AM104
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Iaroslav Postovalov
10/26/2021, 11:43 AMThe most correct solution for Kotlin/JVM is:
Copy code
private val MY_FORMAT = DecimalFormat("0.#")
...
val price = 4.3000
println(MY_FORMAT.format(price)) // 4.3👍 2
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altavir
10/26/2021, 11:45 AMThen you have to use regular expression that ensures that this zero is the last. What @Iaroslav Postovalov is simpler of course, but it works more or less the same inside.
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Iaroslav Postovalov
10/26/2021, 11:47 AMYes, regex solution will be correct but easier to make a mistake with.
➕ 4
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Ilmir Usmanov [JB]
10/27/2021, 2:20 AMWell, stringifying doubles "correctly", which means, choosing least significant bit(s) in a way, that string representation will be the shortest, in short, is not easy, yet straightforward and can be explained with a bit of math. The simplest I found is in EcmaScript 'Number::toString' section, and it is still couple pages long. There is also a paper https://ampl.com/REFS/rounding.pdf and https://netlib.sandia.gov/fp/dtoa.c, which the standard mentions.
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