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# Math.Log10 Method

Visual Studio 2010

Returns the base 10 logarithm of a specified number.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

## Syntax

```public static double Log10(
double d
)
```

#### Parameters

d
Type: System.Double
A number whose logarithm is to be found.

#### Return Value

Type: System.Double
One of the values in the following table.

d parameter

Return value

Positive

The base 10 log of d; that is, log 10 d.

Zero

Negative

Equal to NaN

NaN

Equal to PositiveInfinity

PositiveInfinity

## Remarks

Parameter d is specified as a base 10 number.

## Examples

The following example uses the Log10 method to return the base 10 logarithm for selected values.

```
using System;

public class Example
{
public static void Main()
{
double[] numbers = {-1, 0, .105, .5, .798, 1, 4, 6.9, 10, 50,
100, 500, 1000, Double.MaxValue};

foreach (double number in numbers)
Console.WriteLine("The base 10 log of {0} is {1}.",
number, Math.Log10(number));
}
}
// The example dislays the following output:
//       The base 10 log of -1 is NaN.
//       The base 10 log of 0 is -Infinity.
//       The base 10 log of 0.105 is -0.978810700930062.
//       The base 10 log of 0.5 is -0.301029995663981.
//       The base 10 log of 0.798 is -0.0979971086492706.
//       The base 10 log of 1 is 0.
//       The base 10 log of 4 is 0.602059991327962.
//       The base 10 log of 6.9 is 0.838849090737255.
//       The base 10 log of 10 is 1.
//       The base 10 log of 50 is 1.69897000433602.
//       The base 10 log of 100 is 2.
//       The base 10 log of 500 is 2.69897000433602.
//       The base 10 log of 1000 is 3.
//       The base 10 log of 1.79769313486232E+308 is 308.254715559917.

```

## Version Information

#### .NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

#### .NET Framework Client Profile

Supported in: 4, 3.5 SP1

#### Portable Class Library

Supported in: Portable Class Library

## Platforms

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.