C# DateTime.TryParse and TryParseExact

Use the DateTime.TryParse method and TryParseExact to parse dates and times.

DateTime.TryParse. A string may contain a valid time representation. But there is a possibility it is invalid. There is a way to convert safely the string to a DateTime.DateTime.Parse DateTime

We convert the string into a DateTime instance using the DateTime.TryParse method. This makes errors easy to recover from. A boolean (ok) is returned.

An example. Here we test the DateTime.TryParse method. This is useful—it does the same thing as DateTime.Parse, but does not throw any exceptions.

Return: TryParse returns true if the parse succeeded, and false otherwise. The bool indicates whether the parse was "ok."

Tip: You can use TryParse in the if conditional, and it fills the out DateTime parameter.

If: You do not need to test the result from TryParse in an if-statement, but often this pattern is used to see if the parsing succeeded.

Result: TryParse returns true and then false, indicating the first string contained a valid date representation and the second did not.

True, False

C# program that uses DateTime.TryParse using System; class Program { static void Main() { // Use DateTime.TryParse when input is valid. string input = "2000-02-02"; DateTime dateTime; if (DateTime.TryParse(input, out dateTime)) { Console.WriteLine(dateTime); } // Use DateTime.TryParse when input is bad. string badInput = "???"; DateTime dateTime2; if (DateTime.TryParse(badInput, out dateTime2)) { Console.WriteLine(dateTime2); } else { Console.WriteLine("Invalid"); // <-- Control flow goes here } } } Output 2/2/2000 12:00:00 AM Invalid

TryParseExact. Next we see the DateTime.TryParseExact method. TryParseExact enhances performance and makes your program simpler when you have to deal with lots of invalid date strings.

Tip: In the .NET Framework, the InvariantCulture value is found in System.Globalization, so that namespace must be specified.

Note: You can see in this program that the TryParseExact method succeeds. True is returned by TryParseExact.

C# program that uses TryParseExact using System; using System.Globalization; class Program { static void Main() { string dateString = "Mon 16 Jun 8:30 AM 2008"; string format = "ddd dd MMM h:mm tt yyyy"; DateTime dateTime; if (DateTime.TryParseExact(dateString, format, CultureInfo.InvariantCulture, DateTimeStyles.None, out dateTime)) { Console.WriteLine(dateTime); } } } Output 6/16/2008 8:30:00 AM

Invalid formats. When you need DateTime.TryParseExact, you are usually dealing with invalid formats of dates, or nonexistent dates.

Here: We see an obviously incorrect date, and DateTime.TryParseExact will return false.

Info: The DateTime.TryParseExact method receives a formatting string and converts an input string into a DateTime instance.

String: The formatting string must adhere to the standard .NET Framework style. This requirement steepens the learning curve.

C# program that uses TryParseExact 2 using System; using System.Globalization; class Program { static void Main() { string dateString = "???"; string format = "ddd dd MMM h:mm tt yyyy"; DateTime dateTime; if (DateTime.TryParseExact(dateString, format, CultureInfo.InvariantCulture, DateTimeStyles.None, out dateTime)) { Console.WriteLine(dateTime); } else { Console.WriteLine("Not a date"); } } } Output Not a date

Validity. If you are assured of the validity of your string input (from previous testing in the code), you can use the DateTime.Parse method instead.

Note: Parse has somewhat simpler syntax and is likely faster on valid input. On invalid input, Parse() will not work as well.

Also: There are versions called ParseExact and TryParseExact. They provide a way to assert more control over the parsing algorithm.

A summary. We used the DateTime.TryParse public static method in the C# language. And we proved that it works on different types of strings without throwing exceptions.

The TryParse method uses the tester-doer pattern. It is ideal when you are not positive your input will be valid and want to add error handling or recovery for invalid dates.

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C# DateTime.TryParse and TryParseExact

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