Find Numbers in String

[Regex]::Matches($string, '-?\d*\.?\d+').Value

Details

List integers or floats that are positive or negative inside a string

Example

PS C:\> $string = 'The first 10 digits of pi are 3.1415926535.'
>> [Regex]::Matches($string, '-?\d*\.?\d+').Value

10
3.1415926535