[c#] Parse v. TryParse

What is the difference between Parse() and TryParse()?

int number = int.Parse(textBoxNumber.Text);

// The Try-Parse Method
int.TryParse(textBoxNumber.Text, out number);

Is there some form of error-checking like a Try-Catch Block?

The TryParse method allows you to test whether something is parseable. If you try Parse as in the first instance with an invalid int, you'll get an exception while in the TryParse, it returns a boolean letting you know whether the parse succeeded or not.

As a footnote, passing in null to most TryParse methods will throw an exception.

TryParse does not return the value, it returns a status code to indicate whether the parse succeeded (and doesn't throw an exception).

TryParse and the Exception Tax

Parse throws an exception if the conversion from a string to the specified datatype fails, whereas TryParse explicitly avoids throwing an exception.

If the string can not be converted to an integer, then

• int.Parse() will throw an exception
• int.TryParse() will return false (but not throw an exception)

TryParse does not return the value, it returns a status code to indicate whether the parse succeeded (and doesn't throw an exception).

If the string can not be converted to an integer, then

• int.Parse() will throw an exception
• int.TryParse() will return false (but not throw an exception)

TryParse and the Exception Tax

Parse throws an exception if the conversion from a string to the specified datatype fails, whereas TryParse explicitly avoids throwing an exception.

double.Parse("-"); raises an exception, while double.TryParse("-", out parsed); parses to 0 so I guess TryParse does more complex conversions.

TryParse does not return the value, it returns a status code to indicate whether the parse succeeded (and doesn't throw an exception).

TryParse and the Exception Tax

Parse throws an exception if the conversion from a string to the specified datatype fails, whereas TryParse explicitly avoids throwing an exception.

TryParse does not return the value, it returns a status code to indicate whether the parse succeeded (and doesn't throw an exception).

The TryParse method allows you to test whether something is parseable. If you try Parse as in the first instance with an invalid int, you'll get an exception while in the TryParse, it returns a boolean letting you know whether the parse succeeded or not.

As a footnote, passing in null to most TryParse methods will throw an exception.

If the string can not be converted to an integer, then

• int.Parse() will throw an exception
• int.TryParse() will return false (but not throw an exception)

The TryParse method allows you to test whether something is parseable. If you try Parse as in the first instance with an invalid int, you'll get an exception while in the TryParse, it returns a boolean letting you know whether the parse succeeded or not.

As a footnote, passing in null to most TryParse methods will throw an exception.

I know its a very old post but thought of sharing few more details on Parse vs TryParse.

I had a scenario where DateTime needs to be converted to String and if datevalue null or string.empty we were facing an exception. In order to overcome this, we have replaced Parse with TryParse and will get default date.

Old Code:

dTest[i].StartDate = DateTime.Parse(StartDate).ToString("MM/dd/yyyy");
dTest[i].EndDate = DateTime.Parse(EndDate).ToString("MM/dd/yyyy");

New Code:

DateTime startDate = default(DateTime);
DateTime endDate=default(DateTime);
DateTime.TryParse(dPolicyPaidHistories[i].StartDate, out startDate);
DateTime.TryParse(dPolicyPaidHistories[i].EndDate, out endDate);

Have to declare another variable and used as Out for TryParse.

For the record, I am testing two codes: That simply try to convert from a string to a number and if it fail then assign number to zero.

        if (!Int32.TryParse(txt,out tmpint)) {
            tmpint = 0;
        }

and:

        try {
            tmpint = Convert.ToInt32(txt);
        } catch (Exception) {
            tmpint = 0;
        }

For c#, the best option is to use tryparse because try&Catch alternative thrown the exception

A first chance exception of type 'System.FormatException' occurred in mscorlib.dll

That it is painful slow and undesirable, however, the code does not stop unless Debug's exception are settled for stop with it.

double.Parse("-"); raises an exception, while double.TryParse("-", out parsed); parses to 0 so I guess TryParse does more complex conversions.

I know its a very old post but thought of sharing few more details on Parse vs TryParse.

I had a scenario where DateTime needs to be converted to String and if datevalue null or string.empty we were facing an exception. In order to overcome this, we have replaced Parse with TryParse and will get default date.

Old Code:

dTest[i].StartDate = DateTime.Parse(StartDate).ToString("MM/dd/yyyy");
dTest[i].EndDate = DateTime.Parse(EndDate).ToString("MM/dd/yyyy");

New Code:

DateTime startDate = default(DateTime);
DateTime endDate=default(DateTime);
DateTime.TryParse(dPolicyPaidHistories[i].StartDate, out startDate);
DateTime.TryParse(dPolicyPaidHistories[i].EndDate, out endDate);

Have to declare another variable and used as Out for TryParse.

The TryParse method allows you to test whether something is parseable. If you try Parse as in the first instance with an invalid int, you'll get an exception while in the TryParse, it returns a boolean letting you know whether the parse succeeded or not.

As a footnote, passing in null to most TryParse methods will throw an exception.

If the string can not be converted to an integer, then

• int.Parse() will throw an exception
• int.TryParse() will return false (but not throw an exception)

TryParse and the Exception Tax

Parse throws an exception if the conversion from a string to the specified datatype fails, whereas TryParse explicitly avoids throwing an exception.