C# | Math.Log10() Method

In C#, Math.Log10() is a Math class method. It is used to return the base 10 logarithm of a specified number.

Syntax:

public static double Log10(double val)

Parameter:

val: It is the specified number whose logarithm to be calculated and its type is System.Double.

Return Value: It returns the logarithm of val(base 10 log of val) and its type is System.Double.

Note: Parameter val is always specified as a base 10 number. The return value is depend on the argument passed. Below are some cases:

• If the argument is positive then method will return the natural logarithm or log₁₀(val).
• If the argument is zero, then the result is NegativeInfinity.
• If the argument is Negative(less than zero) or equal to NaN, then the result is NaN.
• If the argument is PositiveInfinity, then the result is PositiveInfinity.
• If the argument is NegativeInfinity, then the result is NaN.

Example:

// C# program to demonstrate working
// of Math.Log10(Double) method
using System;

class Geeks {

    // Main Method
    public static void Main(String[] args)
    {

        // double values whose logarithm
        // to be calculated
        double a = 4.55;
        double b = 0;
        double c = -2.45;
        double nan = Double.NaN;
        double positiveInfinity = Double.PositiveInfinity;
        double negativeInfinity = Double.NegativeInfinity;

        // Input is positive number so output
        // will be logarithm of number
        Console.WriteLine(Math.Log10(a));

        // positive zero as argument, so output
        // will be -Infinity
        Console.WriteLine(Math.Log10(b));

        // Input is negative number so output
        // will be NaN
        Console.WriteLine(Math.Log10(c));

        // Input is NaN so output
        // will be NaN
        Console.WriteLine(Math.Log10(nan));

        // Input is PositiveInfinity so output
        // will be Infinity
        Console.WriteLine(Math.Log10(positiveInfinity));

        // Input is NegativeInfinity so output
        // will be NaN
        Console.WriteLine(Math.Log10(negativeInfinity));
    }
}

Output:

0.658011396657112
-Infinity
NaN
NaN
Infinity
NaN

Reference: https://msdn.microsoft.com/en-us/library/system.math.log10(v=vs.110).aspx