# Global var Meta.parse in loop no vars in Main

**URL:** <https://discourse.julialang.org/t/global-var-meta-parse-in-loop-no-vars-in-main/36358>\
**Category:** New to Julia\
**Created:** [March 22, 2020, 7:47pm UTC](https://discourse.julialang.org/t/global-var-meta-parse-in-loop-no-vars-in-main/36358 "2020-03-22T19:47:23Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![programista](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/programista/32/5372_2.png) [@programista](https://discourse.julialang.org/u/programista)\
**Post date:** [March 22, 2020, 7:47pm UTC](https://discourse.julialang.org/t/global-var-meta-parse-in-loop-no-vars-in-main/36358/1 "2020-03-22T19:47:23Z")

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Where are my vars p1 to p10

```julia
julia> for i=1:10
       var_name=Meta.parse("p$i")
       global var_name
       println(var_name)
       end
p1
p2
p3
p4
p5
p6
p7
p8
p9
p10

julia> varinfo()
name size summary
---------------- ----------- -------
Base Module
Core Module
InteractiveUtils 168.899 KiB Module
Main Module
Plots 24.362 MiB Module
ans 0 bytes Nothing
var_name 0 bytes Symbol

julia> p1
ERROR: UndefVarError: p1 not defined

```

Paul

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<div class="post-metadata">

**Author:** ![yuyichao](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/yuyichao/32/20_2.png) [@yuyichao](https://discourse.julialang.org/u/yuyichao)\
**Post date:** [March 22, 2020, 9:36pm UTC](https://discourse.julialang.org/t/global-var-meta-parse-in-loop-no-vars-in-main/36358/2 "2020-03-22T21:36:33Z")

</div>

> [@programista](#):
>
> global var\_name

This is declaring `var_name` global, not whatever symbol stored in `var_name` to be global. You must use `eval` to create global variables from a runtime value but you also shouldn’t do that. What are you tryingn to accomplish?

* * *

On a side note, use `Symbol("p$i")` instead if you really want to generate variable names.

---

<div class="post-metadata">

**Author:** ![dpsanders](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/dpsanders/32/3573_2.png) [@dpsanders](https://discourse.julialang.org/u/dpsanders)\
**Post date:** [March 23, 2020, 1:07am UTC](https://discourse.julialang.org/t/global-var-meta-parse-in-loop-no-vars-in-main/36358/3 "2020-03-23T01:07:12Z")

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Just use an array:

```julia
p = zeros(10)
p[1]

```

---

<div class="post-metadata">

**Author:** ![programista](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/programista/32/5372_2.png) [@programista](https://discourse.julialang.org/u/programista)\
**Post date:** [March 23, 2020, 5:04pm UTC](https://discourse.julialang.org/t/global-var-meta-parse-in-loop-no-vars-in-main/36358/4 "2020-03-23T17:04:05Z")

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OK, thanks!

```julia
for i=1:10
var_name=Symbol("p$i")
@eval $var_name=rand()
println(var_name)
end

```

Paul

W dniu 2020-03-22 o 22:41, Yichao Yu via JuliaLang pisze:

---

<div class="post-metadata">

**Author:** ![programista](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/programista/32/5372_2.png) [@programista](https://discourse.julialang.org/u/programista)\
**Post date:** [March 23, 2020, 5:05pm UTC](https://discourse.julialang.org/t/global-var-meta-parse-in-loop-no-vars-in-main/36358/5 "2020-03-23T17:05:52Z")

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```julia

for i=1:10

var_name=Symbol("p$i")
@eval $var_name=rand()
println(var_name)
println(@eval $var_name)

end

```

---

<div class="post-metadata">

**Author:** ![dpsanders](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/dpsanders/32/3573_2.png) [@dpsanders](https://discourse.julialang.org/u/dpsanders)\
**Post date:** [March 23, 2020, 6:33pm UTC](https://discourse.julialang.org/t/global-var-meta-parse-in-loop-no-vars-in-main/36358/6 "2020-03-23T18:33:58Z")

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```julia
julia> p = rand(3)

julia> for i in 1:length(p)
           println("p[$i] = ", p[i])
       end
p[1] = 0.4687558912523784
p[2] = 0.6334251270809983
p[3] = 0.2641717376126682

```