# Math.Log10 Method

Silverlight

Returns the base 10 logarithm of a specified number.

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

## Syntax

```'Declaration
<SecuritySafeCriticalAttribute> _
Public Shared Function Log10 ( _
d As Double _
) As Double
```

#### 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.

Sign of d

Returns

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.

```
Module Example
Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
Dim numbers() As Double = {-1, 0, .105, .5, .798, 1, 4, 6.9, 10, 50, _
100, 500, 1000, Double.MaxValue}

For Each number As Double In numbers
Console.WriteLine("The base 10 log of {0} is {1}.", _
number, Math.Log10(number))
Next
End Sub
End Module
' The example displays 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

#### Silverlight

Supported in: 5, 4, 3

#### Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

#### XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

## Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.