C# Math.Log() – Examples
In this tutorial, we will learn about the C# Math.Log() method, and learn how to use this method to the natural logarithm of a number or logarithm of a number in specified base, with the help of examples.
Log(Double d)
Math.Log(d) returns the natural (base e) logarithm of a specified number d
.
Syntax
The syntax of Log() method is
Math.Log(Double d)
where
Parameter | Description |
---|---|
d | The double value whose natural logarithm is to be found. |
Return Value
The method returns a value of type double.
Example 1 – Log(d)
In this example, we will find the natural logarithm of the following values.
- Positive Value
- Negative Value
- Positive Infinity
- Negative Infinity
- Zero
C# Program
using System;
class Example {
static void Main(string[] args) {
Double d, result;
d = 8;
result = Math.Log(d);
Console.WriteLine($"Log({d}) = {result}");
d = -7;
result = Math.Log(d);
Console.WriteLine($"Log({d}) = {result}");
d = Double.PositiveInfinity;
result = Math.Log(d);
Console.WriteLine($"Log({d}) = {result}");
d = Double.NegativeInfinity;
result = Math.Log(d);
Console.WriteLine($"Log({d}) = {result}");
d = 0;
result = Math.Log(d);
Console.WriteLine($"Log({d}) = {result}");
}
}
Output
Log(8) = 2.07944154167984
Log(-7) = NaN
Log(∞) = ∞
Log(-∞) = NaN
Log(0) = -∞
Log(Double d, Double newBase)
Math.Log(d, newBase) returns the logarithm of a specified number d
in a specified base newBase
.
Syntax
The syntax of Log() method is
Math.Log(Double a, Double newBase)
where
Parameter | Description |
---|---|
a | The double value whose logarithm is to be found. |
newBase | The base of the logarithm. |
Return Value
The method returns a value of type double.
Example 2 – Log(d, newBase)
In this example, we will find the logarithm of the following values.
- Positive Value to Base 3
- Negative Value to Base 3
- 3 to the Base 3
- Negative Infinity to Base 3
- Zero to Base 3
C# Program
using System;
class Example {
static void Main(string[] args) {
Double d, newBase, result;
d = 9;
newBase = 3;
result = Math.Log(d, newBase);
Console.WriteLine($"Log({d}) to the base {newBase} = {result}");
d = -7;
newBase = 3;
result = Math.Log(d, newBase);
Console.WriteLine($"Log({d}) to the base {newBase} = {result}");
d = 3;
newBase = 3;
result = Math.Log(d, newBase);
Console.WriteLine($"Log({d}) to the base {newBase} = {result}");
d = Double.NegativeInfinity;
newBase = 3;
result = Math.Log(d, newBase);
Console.WriteLine($"Log({d}) to the base {newBase} = {result}");
d = 0;
newBase = 3;
result = Math.Log(d, newBase);
Console.WriteLine($"Log({d}) to the base {newBase} = {result}");
}
}
Output
Log(9) to the base 3 = 2
Log(-7) to the base 3 = NaN
Log(3) to the base 3 = 1
Log(-∞) to the base 3 = NaN
Log(0) to the base 3 = -∞
Conclusion
In this C# Tutorial, we have learnt the syntax of C# Math.Log() method, and also learnt how to use this method with the help of examples.