Is there a method in the Java library that I can use to find the exponent of a number? Example: If I enter 100, then I expect a return value of 2 (since 102 = 100). If I enter 10000, then I expect a return value of 4 (since 104 = 10000).
Or do I have to keep a counter and keep computing 10counter and check if that is my number. If yes return the counter else increment the counter by 1 and repeat.
What you're looking for is the logarithm:
Math.log10(100); //yields 2.
Definition from google:
Logarithm: a quantity representing the power to which a fixed number (the base) must be raised to produce a given number.
And the doc comments of Math.log10 state:
Returns the base 10 logarithm of a double value
Math.log10() is the standard function found in Math library:
public static double log10(double a)
Returns the base 10 logarithm of a double value. Special cases:
• If the argument is NaN or less than zero, then the result is NaN.
• If the argument is positive infinity, then the result is positive infinity.
• If the argument is positive zero or negative zero, then the result is negative infinity.
• If the argument is equal to 10n for integer n, then the result is n.
The computed result must be within 1 ulp of the exact result. Results must be semi-monotonic.
