TryParse -- best practices [closed]

Question

Closed. This question needs details or clarity. It is not currently accepting answers.

---

Want to improve this question? Add details and clarify the problem by editing this post.

Closed 8 years ago.

Improve this question

I have a set of methods which receive user input as strings and parse it to decimals, ints etc at the header of each method. So, I have same code repeated many times in every method, for instance:

public ..... CreateOrder(....., string rawSourceAmount)
{
    decimal? sourceAmount2 = rawSourceAmount.
        TryToDecimal(XUtils.DecimalFormat(2)); // extension method, wrapper of Decimal.TryParse, returns null if fails
    if (sourceAmount2 == null)
        throw new XBadSourceAmountException(
            sourceSystem.Id, rawSourceAmount);
    decimal sourceAmount = sourceAmount2.Value;

    ..........
}

Why I have sourceAmount2 and sourceAmount? Because later in the method body I actively use sourceAmount, and I do not want each time to write sourceAmount.Value. Is there any way to simplify this templated code?

So, the task is: I have string rawSourceAmount. I need decimal sourceAmount and a place to throw different exception. I do not need sourceAmount2.

Answer 1

Throw this away and read the example here: http://msdn.microsoft.com/en-us/library/f02979c7(v=vs.110).aspx.

You're doing way too much fuss for simple value parsing.

Answer 2

Then change your return type of TryToDecimal method.Make it bool and add a out parameter to your method,then you can check returning result directly,you don't need to define extra nullable variable:

decimal sourceAmount;
if(!rawSourceAmount.TryToDecimal(XUtils.DecimalFormat(2),out sourceAmont)
{
   throw new XBadSourceAmountException(
        sourceSystem.Id, rawSourceAmount);
}