# Function definition inside let-block impacting performance?

**URL:** <https://discourse.julialang.org/t/function-definition-inside-let-block-impacting-performance/110007>\
**Category:** Performance\
**Tags:** question\
**Created:** [February 9, 2024, 8:06pm UTC](https://discourse.julialang.org/t/function-definition-inside-let-block-impacting-performance/110007 "2024-02-09T20:06:28Z")\
**Posts on this page:** 1\
**Showing post:** 4

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**Author:** ![nsajko](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/nsajko/32/221187_2.png) [@nsajko](https://discourse.julialang.org/u/nsajko)\
**Post date:** [February 9, 2024, 8:54pm UTC](https://discourse.julialang.org/t/function-definition-inside-let-block-impacting-performance/110007/4 "2024-02-09T20:54:29Z")

</div>

> [@JuhaHeiskala](#):
>
> julia\> let  
> fib(n) = n \< 2 ? n : fib(n-1) + fib(n-2)

See [Please read: make it easier to help you](https://discourse.julialang.org/t/please-read-make-it-easier-to-help-you/14757)

In particular, put your code into code blocks. That will make it readable and prevent unwanted pings.

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