# A string related MAT file question

**URL:** <https://discourse.julialang.org/t/a-string-related-mat-file-question/78836>\
**Category:** General Usage\
**Tags:** question\
**Created:** [March 31, 2022, 8:19pm UTC](https://discourse.julialang.org/t/a-string-related-mat-file-question/78836 "2022-03-31T20:19:11Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![leon](https://avatars.discourse-cdn.com/v4/letter/l/dc4da7/32.png) [@leon](https://discourse.julialang.org/u/leon)\
**Post date:** [March 31, 2022, 8:19pm UTC](https://discourse.julialang.org/t/a-string-related-mat-file-question/78836/1 "2022-03-31T20:19:11Z")

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My variables are stored as Var1 and Var2 in my MAT file. My goal is to write a loop so that I can read them out one at a time. Why doesn’t the below work?

```julia
using MAT;
F1 = matopen("Path1/File1.mat");
for i ∈ ["Var1", "Var2", ...];
    A = read(F1, $(i));
end
close(F1);

```

This surely work though.  
`A = read(F1, "Var1");`

Isn’t $(1) = “Var1”?

Thanks!

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<div class="post-metadata">

**Author:** ![stevengj](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/stevengj/32/71_2.png) [@stevengj](https://discourse.julialang.org/u/stevengj)\
**Post date:** [March 31, 2022, 8:25pm UTC](https://discourse.julialang.org/t/a-string-related-mat-file-question/78836/2 "2022-03-31T20:25:11Z")

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No dollar signs are needed here. This is just an ordinary use of a variable `i`:

```julia
for i ∈ ["Var1", "Var2", ...]
    A = read(F1, i)
    # do something with A here…
end

```

(Also you don’t need a semicolon after every line.) (And you probably don’t want to close the file until the end of the loop?

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<div class="post-metadata">

**Author:** ![leon](https://avatars.discourse-cdn.com/v4/letter/l/dc4da7/32.png) [@leon](https://discourse.julialang.org/u/leon)\
**Post date:** [March 31, 2022, 8:27pm UTC](https://discourse.julialang.org/t/a-string-related-mat-file-question/78836/3 "2022-03-31T20:27:35Z")

</div>

It works!

Many thanks.