How to convert a symbol to a string of variable it represent

[jlapeyre]

@StevenSiew

answer = @sym D(3 x^4,x)

You might want

julia> @sym answer = D(3x^4, x)
12*:x^3

julia> func = @sym Compile([x], Evaluate(answer))
#3 (generic function with 1 method)

julia> func(5)
1500

or

julia> @sym expr = 3a + b
3:a + :b

julia> func1 = @sym Compile([a, b], Evaluate(expr))
#5 (generic function with 1 method)

julia> func1(1, 2)
5