Define control as variable in Mathematica

Question

When I use Manipulate I can do:

Manipulate[x, {u, 1, 10}]

In reality my controls are many and complicated, so I would prefer to take their defi

Answer 1

This

con = {u, 1, 10};
Manipulate[
 u,
 Evaluate@con
 ]

does work. I suppose it doesn't work without the Evaluate because

Attributes[Manipulate]

shows that Manipulate has the attribute HoldAll (but I may be wrong). To see the effect of this attribute, try this:

SetAttributes[f, HoldAll]
f[con]
f[Evaluate@con]
g[con]
(*
f[con]
f[{u, 1, 10}]
g[{u, 1, 10}]
*)

Thus, it appears that due to the HoldAll atribute, Manipulate simply does not see "inside" con unless you explicitly evaluate it.