# Defining variables in JuMP

**URL:** <https://discourse.julialang.org/t/defining-variables-in-jump/95843>\
**Category:** Optimization (Mathematical)\
**Tags:** question\
**Created:** [March 10, 2023, 7:16am UTC](https://discourse.julialang.org/t/defining-variables-in-jump/95843 "2023-03-10T07:16:59Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![kevinqiao](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/kevinqiao/32/44492_2.png) [@kevinqiao](https://discourse.julialang.org/u/kevinqiao)\
**Post date:** [March 10, 2023, 7:17am UTC](https://discourse.julialang.org/t/defining-variables-in-jump/95843/1 "2023-03-10T07:17:00Z")

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Hello,

I have a question about defining variables in JuMP, normally, the variables are defined as

```julia
@variable(model, testContinusVar)
@variable(model, testIntegerVar, Int)
@variable(model, testBinaryVar, Bin)

```

And what if I define variables as

```julia
testContinusVar = @variable(model, testContinusVar)
testIntegerVar = @variable(model, testIntegerVar, Int)
testBinaryVar = @variable(model, testBinaryVar, Bin)

```

Are the two defining ways the same? I’ve tested it in a small case, and it seems they are the same, while I’m not pretty sure from the bottom implementation method, so could anyone answer it?

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**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:** [March 10, 2023, 8:38am UTC](https://discourse.julialang.org/t/defining-variables-in-jump/95843/2 "2023-03-10T08:38:49Z")

</div>

These are exactly the same.

Is this part of the documentation clear?

> **[Variables · JuMP](https://jump.dev/JuMP.jl/stable/manual/variables/#variable_names_and_bindings)**
>
> Documentation for JuMP.

Or could I improve it?

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<div class="post-metadata">

**Author:** ![kevinqiao](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/kevinqiao/32/44492_2.png) [@kevinqiao](https://discourse.julialang.org/u/kevinqiao)\
**Post date:** [March 10, 2023, 9:59am UTC](https://discourse.julialang.org/t/defining-variables-in-jump/95843/3 "2023-03-10T09:59:01Z")

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yep, it’s not so clear. Maybe it can be improved by adding:

- (Special) Named JuMP variables have the form @variable(model, x), which exactly equals x = @variable(model, x)

though the above is not a difference between the name that a variable is registered under and the `String` name used for printing.

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**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:** [March 15, 2023, 2:13am UTC](https://discourse.julialang.org/t/defining-variables-in-jump/95843/4 "2023-03-15T02:13:47Z")

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How’s this?

> <https://github.com/jump-dev/JuMP.jl/pull/3284>
>
> Question from Discourse: https://discourse.julialang.org/t/defining-variables-in…-jump/95843/2

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<div class="post-metadata">

**Author:** ![kevinqiao](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/kevinqiao/32/44492_2.png) [@kevinqiao](https://discourse.julialang.org/u/kevinqiao)\
**Post date:** [March 20, 2023, 2:46am UTC](https://discourse.julialang.org/t/defining-variables-in-jump/95843/5 "2023-03-20T02:46:46Z")

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It looks better, thank you. @odow