In PowerShell, how can I test if a variable holds a numeric value?

Question

In PowerShell, how can I test if a variable holds a numeric value?

Currently, I\'m trying to do it like this, but it always seems to return false.

Answer 1

Modify your filter like this:

filter isNumeric {
    [Helpers]::IsNumeric($_)
}

function uses the $input variable to contain pipeline information whereas the filter uses the special variable $_ that contains the current pipeline object.

Edit:

For a powershell syntax way you can use just a filter (w/o add-type):

filter isNumeric() {
    return $_ -is [byte]  -or $_ -is [int16]  -or $_ -is [int32]  -or $_ -is [int64]  `
       -or $_ -is [sbyte] -or $_ -is [uint16] -or $_ -is [uint32] -or $_ -is [uint64] `
       -or $_ -is [float] -or $_ -is [double] -or $_ -is [decimal]
}