Variables in if statement

Hi iainh,

I know what you mean :). M is a "flow" language, which is quite different to VBA, which is "transactional".

Therefore, you are programming transitions rather than states  as in a more traditional languages.

I think, this is quite important to bear in mind this (seemgly simple) difference. For me, comming from VB + C# this was quite a change in paradigm.

In your case, this is enough to see each conditions as a separate function (kind of a delegate in C# if you wish). Therefore, it is possible to record it as return "Actual Start is a future date" if condition1 is met, combine with return "Task Ends before it begins" if condition 2 is met:

#"Added custom" = 
    Table.AddColumn(#"Changed column type", "Error Checking", 
        each
            Text.Combine(
                {
                    if [Task Actual Start Date] <> null and [Task Actual Start Date] > Date.From(DateTime.LocalNow()) then "Actual Start is a future date" else "",
                    if ([Task Actual Finish Date] <> null and [Task Actual Start Date] <> null) and [Task Actual Finish Date] < [Task Actual Start Date] then "Task Ends before it begins" else ""
                },
                " AND "
    ) 

I do not test the above, but I guess even if this does not work straight from the source, you will be able to see the idea and tweak it to make it work.

Cheers,

John