# Expression #= none:3 =# should not be used as a variable name

**URL:** <https://discourse.julialang.org/t/expression-none-3-should-not-be-used-as-a-variable-name/60422>\
**Category:** Optimization (Mathematical)\
**Tags:** question, jump\
**Created:** [May 2, 2021, 3:19pm UTC](https://discourse.julialang.org/t/expression-none-3-should-not-be-used-as-a-variable-name/60422 "2021-05-02T15:19:04Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![BYS](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bys/32/25384_2.png) [@BYS](https://discourse.julialang.org/u/BYS)\
**Post date:** [May 2, 2021, 3:19pm UTC](https://discourse.julialang.org/t/expression-none-3-should-not-be-used-as-a-variable-name/60422/1 "2021-05-02T15:19:04Z")

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If I write

```julia
using JuMP
@variable(pro,begin
    t1>=1 
    t2>=2 
    t3>=3
end)

```

I find a error like this

```julia
ERROR: LoadError: Expression #= none:3 =# should not be used as a variable name. Use the "anonymous" syntax #= none:3 =# = @variable(model, ...) instead.

```

I want to know if there are errors for expression or just the version problem of julia and JuMP?

---

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**Author:** ![chris-b1](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chris-b1/32/14165_2.png) [@chris-b1](https://discourse.julialang.org/u/chris-b1)\
**Post date:** [May 2, 2021, 7:02pm UTC](https://discourse.julialang.org/t/expression-none-3-should-not-be-used-as-a-variable-name/60422/2 "2021-05-02T19:02:18Z")

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Looks like you probably want the `@variables` (note the s) macro instead?

[https://jump.dev/JuMP.jl/stable/manual/variables/#variables](https://jump.dev/JuMP.jl/stable/manual/variables/#variables)

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<div class="post-metadata">

**Author:** ![odow](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/odow/32/28685_2.png) [@odow](https://discourse.julialang.org/u/odow)\
**Post date:** [May 3, 2021, 1:35am UTC](https://discourse.julialang.org/t/expression-none-3-should-not-be-used-as-a-variable-name/60422/3 "2021-05-03T01:35:58Z")

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We should probably throw a better error in this case. I’ve opened an issue: [Improve error when singular macro used instead of plural · Issue #2582 · jump-dev/JuMP.jl · GitHub](https://github.com/jump-dev/JuMP.jl/issues/2582)

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<div class="post-metadata">

**Author:** ![BYS](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bys/32/25384_2.png) [@BYS](https://discourse.julialang.org/u/BYS)\
**Post date:** [May 3, 2021, 1:44am UTC](https://discourse.julialang.org/t/expression-none-3-should-not-be-used-as-a-variable-name/60422/4 "2021-05-03T01:44:26Z")

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Thank you very much for you help. It should be “variables”.

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<div class="post-metadata">

**Author:** ![BYS](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bys/32/25384_2.png) [@BYS](https://discourse.julialang.org/u/BYS)\
**Post date:** [May 3, 2021, 1:48am UTC](https://discourse.julialang.org/t/expression-none-3-should-not-be-used-as-a-variable-name/60422/5 "2021-05-03T01:48:16Z")

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OK 👌