- 1 year ago
Using Powershell [DateTime]::ParseExact - Funny Strings?
When using [DateTime]::ParseExact
in PowerShell, you need to provide a format string that matches the expected format of the input string. If the input string does not match the format specified in the format string, you may encounter unexpected results or errors.
Regarding "Funny Strings," it refers to providing input strings that do not match the expected format. These can include invalid or unconventional date and time representations that may cause issues with parsing.
For example, if you have a format string yyyy-MM-dd
to parse dates in the format "YYYY-MM-DD," providing an input string like "2022-13-32" (which is not a valid date) would result in an error.
Here are a few considerations when using [DateTime]::ParseExact
:
Format String: Ensure that the format string accurately represents the expected format of the input string. Refer to the .NET Custom Date and Time Format Strings documentation for guidance on constructing the format string: https://docs.microsoft.com/en-us/dotnet/standard/base-types/custom-date-and-time-format-strings
Input Validation: Validate the input string before attempting to parse it. You can use the
[DateTime]::TryParseExact
method, which returns a Boolean indicating whether the parsing was successful or not.powershell$inputString = "2022-13-32"
$formatString = "yyyy-MM-dd"
$parsedDate = $null
$success = [DateTime]::TryParseExact($inputString, $formatString, [System.Globalization.CultureInfo]::InvariantCulture, [System.Globalization.DateTimeStyles]::None, [ref]$parsedDate)
if ($success) {
# Parsing was successful, use $parsedDate
} else {
# Invalid input string
Write-Host "Invalid date format"
}
The
$success
variable will beTrue
if the parsing is successful, and$parsedDate
will contain the parsedDateTime
value.Culture and Locale Considerations: Be aware of cultural and locale-specific variations in date and time representations. Specify the appropriate culture or use
[System.Globalization.CultureInfo]::InvariantCulture
if you want to ensure consistent parsing regardless of the current culture.
By validating the input and using the correct format string, you can ensure accurate parsing using [DateTime]::ParseExact
or [DateTime]::TryParseExact
in PowerShell. Handling unexpected or "funny" strings may require additional error checking or input validation logic based on your specific use case.