Refactoring messy if else statement - if-statement

Question

I am working on a legacy code base which has the following snippet:
if ((results[0].Length == 0))
customerName = "";
else
customerName = results[0].Substring(18);
if ((results[1].Length == 0))
meterSerialNumber = "";
else
meterSerialNumber = results[1];
if ((results[2].Length == 0))
customerID = "";
else
customerID = results[2];
if ((results[3].Length == 0))
meterCreditAmount = "";
else
meterCreditAmount = results[3];
if ((results[4].Length == 0))
debtInstallmentDeduction = "";
else
debtInstallmentDeduction = results[4];
if ((results[5].Length == 0))
vatOnEnergyAmount = "";
else
vatOnEnergyAmount = results[5];
if ((results[6].Length == 0))
vatOnDebt = "";
else
vatOnDebt = results[6];
if ((results[7].Length == 0))
outstandingDebtAmount = "";
else
outstandingDebtAmount = results[7];
if ((results[8].Length == 0))
tariffCategory = "";
else
tariffCategory = results[8];
if ((results[9].Length == 0))
tariffId = "";
else
tariffId = results[9];
if ((results[10].Length == 0))
encryptedToken1 = "";
else
encryptedToken1 = results[10];
if ((results[11].Length == 0))
encryptedToken2 = "";
else
encryptedToken2 = results[11];
if ((results[12].Length == 0))
encryptedToken3 = "";
else
encryptedToken3 = results[12];
if ((results[13].Length == 0))
encryptedToken4 = "";
else
encryptedToken4 = results[13];
if ((results[14].Length == 0))
systemMessage = "";
else
systemMessage = results[14];
if ((results[15].Length == 0))
customerMessage = "";
else
customerMessage = results[15];
if ((results[16].Length == 0))
predefinedMessage = "";
else
predefinedMessage = results[16];
if ((results[17].Length == 0))
transactionAcknowledgeNumber = "";
else
transactionAcknowledgeNumber = results[17];
What would be the best way to refactor this for acceptable coding standards? Would it be acceptable to make this a case statement instead?

Answer 1

This is not a case-wise execution so it can't be refactored to a switch-case. However it can be converted to functional code and then it factored out into a separate method so that the "ugly" part is hidden behind a method call.
Step#1 - Making the code functional
Here, we rewrite the code by following functional code writing practices. The rewritten code will look like:
customerName = (results[0].Length == 0) ? "" : results[0].Substring(18);
meterSerialNumber = (results[1].Length == 0) ? "" : results[1];
customerID = (results[2].Length == 0) ? "" : results[2];
meterCreditAmount = (results[3].Length == 0) ? "" : results[3];
debtInstallmentDeduction = (results[4].Length == 0) ? "" : results[4];
vatOnEnergyAmount = (results[5].Length == 0) ? "" : results[5];
.
.
.
transactionAcknowledgeNumber = (results[17].Length == 0) ? "" : results[17];
There are numerous advantages of writing the code this way. Important ones include:
terseness of code;
values being initialized at one place (by means of ternary operator) instead of two (one in if and another in else clause).
Step#2 - Factoring out the method
Now that the values are being initialized functionally, you can create a class (or you may be already having this class) containing the properties customerName, meterSerialNumber, ..., transactionAcknowledgeNumber. Either the constructor of the class can be designed to read the results and populate the class members or you may write a method to read the results. So it will look like:
ResultValues resultVal = new ResultValues();
resultVal.Read(results);
.
.
.
//Accessing the values later in the code
Print(resultVal.customerName);
...
PS:
1. I admit that ResultValues may not be a good class to make. Alternatively, you may create multiple classes by clubbing the related data and then have the Read() method of those classes read the values from results.
2. The essential idea of Step#2 is to factor out the "ugly" part to another simple and readable method call(s).