# Julia test if number is Inf

**URL:** <https://discourse.julialang.org/t/julia-test-if-number-is-inf/26287>\
**Category:** New to Julia\
**Created:** [July 12, 2019, 12:39pm UTC](https://discourse.julialang.org/t/julia-test-if-number-is-inf/26287 "2019-07-12T12:39:41Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Luigi\_Marongiu](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/luigi_marongiu/32/7909_2.png) [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Post date:** [July 12, 2019, 12:39pm UTC](https://discourse.julialang.org/t/julia-test-if-number-is-inf/26287/1 "2019-07-12T12:39:41Z")

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Hello  
is there a simple way to test if a variable is Inf? something like isnan(x)?

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<div class="post-metadata">

**Author:** ![fredrikekre](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/fredrikekre/32/1688_2.png) [@fredrikekre](https://discourse.julialang.org/u/fredrikekre)\
**Post date:** [July 12, 2019, 12:42pm UTC](https://discourse.julialang.org/t/julia-test-if-number-is-inf/26287/2 "2019-07-12T12:42:12Z")

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```julia
help?> isinf

  isinf(f) -> Bool

  Test whether a number is infinite.

```