Using log base 10 in a formula in Java

Question

I'm trying to write a Java program that can take values and put them into a formula involving log base 10.

How can I calculate log₁₀ in Java?

Answer 1

It looks like Java actually has a log10 function:

Math.log10(x) 

Otherwise, just use math:

Math.log(x) / Math.log(10) 

http://docs.oracle.com/javase/7/docs/api/java/lang/Math.html

Answer 2

Math.log10(x) 

suffices for floating-point numbers.

If you need integer log base 10, and you can use third-party libraries, Guava provides IntMath.log10(int, RoundingMode). (Disclosure: I contribute to Guava.)