Question

int expenseCode;
if (int.TryParse(sourceRecord.ExpenseCode, out expenseCode) && _ExpenseCodeLookup.ContainsKey(expenseCode))
{
     destRow.PROFIT_CENTER_NAME = _ExpenseCodeLookup[expenseCode];
}
else
     destRow.PROFIT_CENTER_NAME = "Unknown";

The thing I am conerned about is will the first expression always be run (setting expenseCode in the process) before the second operation?

Answer 1

That’s fine. && is short-circuiting in C#, and the out parameter will definitely have been assigned the appropriate value by TryParse before ContainsKey is called.

On the other hand, you could use the same trick again to fetch the value:

string profitCenter;
int expenseCode;
if (int.TryParse(sourceRecord.ExpenseCode, out expenseCode) && 
    _ExpenseCodeLookup.TryGetValue(expenseCode, out profitCenter))
{
    destRow.PROFIT_CENTER_NAME = profitCenter;
}
else
{
    destRow.PROFIT_CENTER_NAME = "Unknown";
}

This way you’re only doing the lookup of the expense code once.