How to use With on previously defined expressions [duplicate]

Question

The command With[{x = 1}, x] outputs 1.

The command t = x; With[{x = 1}, t] outputs x.

I expected this second input to give the same answer. How can I modify my code so it behaves in this way?

$\begingroup$ To give you an idea: try t=x; With[{x=1}, {x, t}]. $\endgroup$
– J. M.'s missing motivation ♦
Nov 11, 2015 at 14:05 — J. M.'s missing motivation, Nov 11, 2015 at 14:05

ybeltukov · Accepted Answer · 2015-11-11 14:22:16Z

4

I think you are confusing the behaviour of With and Block

t = x; Block[{x = 1}, t]
(* 1 *)

answered Nov 11, 2015 at 14:22

ybeltukov

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$\begingroup$ Yes, this works better for my more complicated actual situation. Thanks :) $\endgroup$
– Tom
Nov 11, 2015 at 14:42

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Coolwater · Accepted Answer · 2015-11-11 14:07:28Z

5

t = x; With[{x = 1}, Evaluate[t]]

answered Nov 11, 2015 at 14:07

Coolwater

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2 Answers 2