Which of the following is not an available math function?

• A. pop
• B. exp
• C. floor
• D. round

Answer: (A)

The important idea here is telling apart true mathematical operations from non-math data manipulations. In FME’s expression language, exp, floor, and round are standard numeric functions: exp computes e to the power of a number, floor rounds down to the nearest integer, and round rounds to the nearest integer. These take numeric input and return a numeric result.

Pop, on the other hand, isn’t a math function. It’s used for data structure or collection manipulation (removing or retrieving an item from a list/stack, for example) and doesn’t perform a numeric calculation. So it isn’t available as a math function, making it the correct choice for the question. If you try to use it in a numeric expression, it wouldn’t produce a numeric result and would cause an expression error.