VLOOKUP by Combining 2 Columns to Form a Unique Key

Question

For the following table,

I want to look up the value in col C. Since the values in col A an

Answer 1

The way I usually do it is by concatenating the values separated by a pipe character (|). See the formula in the screenshot below.

Then you can vlookup using the concatenated key.

=VLOOKUP("1|foo",$C$1:$D$7,2,FALSE)