Check for null before continuing LINQ and return value as "-"

Question

I have this code.

DisplayTimeStamp = PredictionTableList
    .Where(x => x.ContextTimestamp != null)
    .Select(x => x.ContextTimestamp)
    .FirstOrDefault();

It returns the first data of the table. Sometimes PredictionTableList is null, how do I check for this and return the null value as "-"?

Answer 1

Option 1: An if-else statement to check whether PredictionTableList is null.

if (PredictionTableList == null)
    DisplayTimeStamp = "-";
else
    DisplayTimeStamp = PredictionTableList.Where(x => x.ContextTimestamp != null)
        .Select(x => x.ContextTimestamp)
        .FirstOrDefault();

Option 2: Ternary operator

DisplayTimeStamp = PredictionTableList == null
    ? "-"
    : PredictionTableList.Where(x => x.ContextTimestamp != null)
        .Select(x => x.ContextTimestamp)
        .FirstOrDefault();