Variables referring to other variables within Module

Question

The following doesn't work:

Lol[x_, y_] = Module[ {w=x+1, z = w + 1}, z]

because z refers to w. Is there a way to make it so that variable definitions within Module can refer to other variable definitions?

This is similar to let constructs in other languages.

Try this: Lol[x_, y_] := Module[{w, z}, w = x + 1; z = w + 1] — MelaGo, Commented May 23, 2019 at 22:21

Carl Woll · Accepted Answer · 2019-05-23 22:34:17Z

5

I think you meant to use Lol[x_, y_]. At any rate, you can use With to do this, although the syntax coloring is bad:

Lol[x_, y_] := With[
    {w = x + 1},
    {z = w + 1},
    z
]

Then:

Lol[2, 3]

4

The syntax coloring should be fixed with the next version of Mathematica.

answered May 23, 2019 at 22:34

Carl Woll

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1

$\begingroup$ If With is the answer then it is a duplicate, if OP showed only a minimal example and Module is a key here, then it is not the answer. I know you know but readers may not know why Module was replaced with With without a word of explanation. $\endgroup$
– Kuba
Commented May 24, 2019 at 9:12
$\begingroup$ @Kuba The original post refers to the "let constructs" found elsewhere. That pretty much implies a With-like approach should be used, i.e. Module should not be a key requirement. $\endgroup$
– Daniel Lichtblau
Commented May 24, 2019 at 15:22
1

$\begingroup$ @DanielLichtblau thanks the comment. Seems like my initial comment is still valid though. $\endgroup$
– Kuba
Commented May 27, 2019 at 13:56

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