# Is there any way in Julia to perform string interpolation after the string is decl

**URL:** <https://discourse.julialang.org/t/is-there-any-way-in-julia-to-perform-string-interpolation-after-the-string-is-decl/55688>\
**Category:** General Usage\
**Tags:** string-interpolation\
**Created:** [February 20, 2021, 5:03pm UTC](https://discourse.julialang.org/t/is-there-any-way-in-julia-to-perform-string-interpolation-after-the-string-is-decl/55688 "2021-02-20T17:03:19Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![BridgeBot](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bridgebot/32/21491_2.png) [@BridgeBot](https://discourse.julialang.org/u/BridgeBot)\
**Post date:** [February 20, 2021, 5:03pm UTC](https://discourse.julialang.org/t/is-there-any-way-in-julia-to-perform-string-interpolation-after-the-string-is-decl/55688/1 "2021-02-20T17:03:19Z")

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Is there any way in Julia to perform string interpolation after the string is declared?

For example in python I can do:

```julia
&gt; x = "Hello, {}"
&gt; x.format("friend")
'Hello, friend'

```

So I can declare `x` with placeholders, and later decide what goes in the placeholder. Is there any equivalent to this in Julia?

Thanks!

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**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:** [February 20, 2021, 5:37pm UTC](https://discourse.julialang.org/t/is-there-any-way-in-julia-to-perform-string-interpolation-after-the-string-is-decl/55688/2 "2021-02-20T17:37:12Z")

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> [@BridgeBot](#):
>
> So I can declare `x` with placeholders, and later decide what goes in the placeholder. Is there any equivalent to this in Julia?

There are packages for this, e.g. the C-style [Printf standard library](https://docs.julialang.org/en/v1/stdlib/Printf/) or the Python-style [Formatting.jl](https://github.com/JuliaIO/Formatting.jl), and also [Mustache.jl](https://github.com/jverzani/Mustache.jl).