Question

I have a function called FindSpecificRowValue that takes in a datatable and returns the row number that contains a particular value. If that value isn’t found, I want to indicate so to the calling function.

Is the best approach to:

1. Write a function that returns false if not found, true if found, and the found row number as a byref/output parameter, or
2. Write a function that returns an int and pass back -999 if the row value isn’t found, the row number if it is?

Answer 1

Personally I would not do either with that method name.

I would instead make two methods:

TryFindSpecificRow FindSpecificRow 

This would follow the pattern of Int32.Parse/TryParse, and in C# they could look like this:

public static Boolean TryFindSpecificRow(DataTable table, out Int32 rowNumber) {     if (row-can-be-found)     {         rowNumber = index-of-row-that-was-found;         return true;     }     else     {         rowNumber = 0; // this value will not be used anyway         return false;     } }  public static Int32 FindSpecificRow(DataTable table) {     Int32 rowNumber;       if (TryFindSpecificRow(table, out rowNumber))         return rowNumber;     else         throw new RowNotFoundException(String.Format('Row {0} was not found', rowNumber)); } 

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Edit: Changed to be more appropriate to the question.