# What is julia lang equivalent to R's %in%?
**URL:** https://discourse.julialang.org/t/what-is-julia-lang-equivalent-to-rs-in/56314
**Category:** New to Julia
**Created:** [March 2, 2021, 9:52am UTC](https://discourse.julialang.org/t/what-is-julia-lang-equivalent-to-rs-in/56314 "2021-03-02T09:52:08Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)
#### Post date: [March 2, 2021, 9:52am UTC](https://discourse.julialang.org/t/what-is-julia-lang-equivalent-to-rs-in/56314/1 "2021-03-02T09:52:09Z")
Hello, I have a vector:
```julia
b = ["NC_001422", "NZ_CP008698", "NZ_CP016318" , "NZ_CP010905", "NZ_CP019649",
"NZ_CP029707" , "NZ_CP011102", "NC_006905", "NC_006905",
"NC_009142", "NC_006322", "NC_013971", "NC_017451", "NC_014494",
"NC_017340", "NC_008024", "NC_011375", "NC_007296", "NC_008022",
"NC_004070", "NC_003197", "NC_012225", "NC_011566", "NC_012751",
"NC_005362", "NC_002976", "NC_026268", "NC_002737"]
```
I would like to test if the object “AC\_000006” is present in vector b. What would be Julia’s equivalent to R’s %in%?
Thank you
---
### Author:  [@jonathanBieler](https://discourse.julialang.org/u/jonathanBieler)
#### Post date: [March 2, 2021, 9:59am UTC](https://discourse.julialang.org/t/what-is-julia-lang-equivalent-to-rs-in/56314/2 "2021-03-02T09:59:54Z")
```julia
julia> "NC_011566" ∈ b
true
```
You have to type `\in` + tab to get ∈. Otherwise you can use `"NC_011566" in b` or `in("NC_011566", b)` (they are all the same thing).
---
### Author:  [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)
#### Post date: [March 2, 2021, 10:06am UTC](https://discourse.julialang.org/t/what-is-julia-lang-equivalent-to-rs-in/56314/3 "2021-03-02T10:06:15Z")
Thanks
---
### Author:  [@mbauman](https://discourse.julialang.org/u/mbauman)
#### Post date: [March 2, 2021, 1:23pm UTC](https://discourse.julialang.org/t/what-is-julia-lang-equivalent-to-rs-in/56314/4 "2021-03-02T13:23:17Z")
No need to reach for unicode in this particular case:
```julia
julia> "NC_011566" in b
true
```
As with all operators, though, you can also just call it as a normal function:
```julia
julia> in("NC_011566", b)
true
```
Unlike R, there’s not a general mechanism for putting an arbitrary function in infix position, and this is the only “word” that works like this. All other infix operations are symbols of some sort — which you can define and use yourself.
---
### Author:  [@DNF](https://discourse.julialang.org/u/DNF)
#### Post date: [March 2, 2021, 1:31pm UTC](https://discourse.julialang.org/t/what-is-julia-lang-equivalent-to-rs-in/56314/5 "2021-03-02T13:31:24Z")
> [@mbauman](#):
>
> this is the only “word” that works like this.
```julia
jl> 3 isa Int
true
```
😉
This is not a generic function, though.
---
### Author:  [@mbauman](https://discourse.julialang.org/u/mbauman)
#### Post date: [March 2, 2021, 1:35pm UTC](https://discourse.julialang.org/t/what-is-julia-lang-equivalent-to-rs-in/56314/6 "2021-03-02T13:35:38Z")
Ah, thanks. I knew as I was writing that sentence that I was likely to be wrong. If I were feeling snarky I’d say that “isa” isn’t a (dictionary) word! 😛
---
### Author:  [@stevengj](https://discourse.julialang.org/u/stevengj)
#### Post date: [March 2, 2021, 1:42pm UTC](https://discourse.julialang.org/t/what-is-julia-lang-equivalent-to-rs-in/56314/7 "2021-03-02T13:42:55Z")
> [@mbauman](#):
>
> Unlike R, there’s not a general mechanism for putting an arbitrary function in infix position
You could resurrect [GitHub - Ismael-VC/InfixFunctions.jl: Julia infix function hack.](https://github.com/SalchiPapa/InfixFunctions.jl)
---
### Author:  [@simeonschaub](https://discourse.julialang.org/u/simeonschaub)
#### Post date: [March 2, 2021, 1:54pm UTC](https://discourse.julialang.org/t/what-is-julia-lang-equivalent-to-rs-in/56314/8 "2021-03-02T13:54:21Z")
But `where` certainly is 😉