Evaluate[] seems to not work inside Button[]

Any idea how to get this to work?

y = {开发者_运维问答}; Table[Button[x, AppendTo[y, Evaluate[x]]], {x, 5}]

Result: Click [1] , click [2], get {6,6}

I'm trivializing the actual task, but the goal is to set what a button does inside a Map or a Table or ParallelTable.

Please Help!

EDIT

Figured it out... Evaluate works at first level only. Here, it's too deep. So I used ReplaceRule:

Remove[sub]; y = {}; Table[Button[x, AppendTo[y, sub]] /. sub -> x, {x, 5}]

This is a job for With. With is used to insert an evaluated expression into another expression at any depth -- even into parts of the expression that are not evaluated right away like the second argument to Button:

y = {}; Table[With[{x = i}, Button[x, AppendTo[y, x]]], {i, 5}]

In simple cases like this, some people (myself included) prefer to use the same symbol (x in this case) for both the With and Table variables, thus:

y = {}; Table[With[{x = x}, Button[x, AppendTo[y, x]]], {x, 5}]

Replacement rules and pure functions offer concise alternatives to With. For example:

y={}; Range[5] /. x_Integer :> Button[x, AppendTo[y, x]]

or

y = {}; Replace[Range[5], x_ :> Button[x, AppendTo[y, x]], {1}]

or

y = {}; Array[Button[#, AppendTo[y, #]] &, {5}]

or

y = {}; Button[#, AppendTo[y, #]] & /@ Range[5]

For another example comparing these techniques, see my post here, where they are applied to a problem of creating a list of pure functions with parameter embedded in their body (closures).

Evaluate works at first level only. Here, it's too deep. So I used ReplaceRule:

Remove[sub]; y = {}; Table[ Button[x, AppendTo[y, sub]] /. sub -> x, {x, 5}]