How to check if the double or float value has only one decimal place in Java

Question

For eg. there is a float value 1345.1, then how do I check whether it has only one decimal place and not more than that?

is this a String representation of a float? Otherwise the value may not be exactly what you think it is anyway. If this is a String then just test the length after the dot. See https://stackoverflow.com/questions/588004/is-floating-point-math-broken — Scary Wombat, Jul 09 '20 at 06:58
Good point, I can do that. This is the String representation, so I can test the length after the dot. Thanks, this will work. — Shiv Jirwankar, Jul 09 '20 at 07:00

score 1 · Answer 1 · answered Jul 09 '20 at 07:06

1

Theoretically you cannot have a float number as precise as this, it always has more digits unless someone already rounded it for you. Is it the case? If that's the case I think you could parse it as a String and count the digits after the dot. I would do it like this:

float floatNumber = 24.04;
String floatAsString= String.valueOf(floatNumber);
int indexOfDecimal = floatAsString.indexOf(".");
if(floatAsString.substring(indexOfDecimal).length == 1) {return true;}

answered Jul 09 '20 at 07:06

Simone Lungarella

301
1
4
15

1

you can use `if(floatAsString.length() - indexOfDecimal + 1 == 1)` – deadshot Jul 09 '20 at 07:10
How would it work with https://stackoverflow.com/questions/588004/is-floating-point-math-broken ? – Scary Wombat Jul 09 '20 at 07:27

How to check if the double or float value has only one decimal place in Java

1 Answers1