# Findall((in)) returns non-sorted array for Int64
**URL:** https://discourse.julialang.org/t/findall-in-returns-non-sorted-array-for-int64/20556
**Category:** New to Julia
**Tags:** question
**Created:** [February 7, 2019, 5:14pm UTC](https://discourse.julialang.org/t/findall-in-returns-non-sorted-array-for-int64/20556 "2019-02-07T17:14:01Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@ezgikurt](https://discourse.julialang.org/u/ezgikurt)
#### Post date: [February 7, 2019, 5:14pm UTC](https://discourse.julialang.org/t/findall-in-returns-non-sorted-array-for-int64/20556/1 "2019-02-07T17:14:01Z")
Hi,
I’m trying to find where the elements of an Array{Int64,1} are indexed in another Array{Int64,1}. I’m trying something like the following (but b and a are much longer).
```julia
b = [7;3];
a = 1:10;
c = findall((in)(b), a);
c = [3;7]
```
Is there a way to have this sorted? i.e I want c to be [7;3].
---
### Author:  [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)
#### Post date: [February 7, 2019, 5:16pm UTC](https://discourse.julialang.org/t/findall-in-returns-non-sorted-array-for-int64/20556/2 "2019-02-07T17:16:09Z")
It is sorted — in ascending order. Use `reverse(c)`.
PS: also, please [quote your code](https://discourse.julialang.org/t/psa-how-to-quote-code-with-backticks/7530).
---
### Author:  [@ezgikurt](https://discourse.julialang.org/u/ezgikurt)
#### Post date: [February 7, 2019, 5:56pm UTC](https://discourse.julialang.org/t/findall-in-returns-non-sorted-array-for-int64/20556/3 "2019-02-07T17:56:40Z")
Hi, unfortunately that doesn’t work - i think i wasn’t clear in my example, here’s a better one. `a` is not in ascending order, it is just an Array of random integers and `b` has more than 2 elements. See the following example:
```julia
a = [3;11;18;7;27;5];
b = [3;5;7];
c = findall((in)(b),a);
c
3-element Array{Int64,1}:
1
4
6
reverse(c)
3-element Array{Int64,1}:
6
4
1
```
But i want it to return [1;6;4] of course.
---
### Author:  [@mbauman](https://discourse.julialang.org/u/mbauman)
#### Post date: [February 7, 2019, 5:58pm UTC](https://discourse.julialang.org/t/findall-in-returns-non-sorted-array-for-int64/20556/4 "2019-02-07T17:58:36Z")
You want a different operation entirely: [`indexin`](https://docs.julialang.org/en/v1/base/collections/#Base.indexin).
```julia
julia> indexin(b, a)
3-element Array{Union{Nothing, Int64},1}:
1
6
4
```
---
### Author:  [@ezgikurt](https://discourse.julialang.org/u/ezgikurt)
#### Post date: [February 7, 2019, 6:17pm UTC](https://discourse.julialang.org/t/findall-in-returns-non-sorted-array-for-int64/20556/5 "2019-02-07T18:17:12Z")
great, thanks!