# "unzip" a vector of Pairs
**URL:** https://discourse.julialang.org/t/unzip-a-vector-of-pairs/1346
**Category:** General Usage
**Tags:** question
**Created:** [January 7, 2017, 3:55pm UTC](https://discourse.julialang.org/t/unzip-a-vector-of-pairs/1346 "2017-01-07T15:55:03Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)
#### Post date: [January 7, 2017, 3:55pm UTC](https://discourse.julialang.org/t/unzip-a-vector-of-pairs/1346/1 "2017-01-07T15:55:03Z")
Given a `Vector` of `Pair`s, what’s an idiomatic way of getting a vector of first and second elements in each `Pair`? MWE:
```julia
x = [Pair(x,2*x) for x in 1:5]
```
then
```julia
julia> collect.(collect(zip(((a,b) for (a,b) in x)...))) # works, but convoluted
2-element Array{Array{Int64,1},1}:
[1,2,3,4,5]
[2,4,6,8,10]
```
---
### Author:  [@stevengj](https://discourse.julialang.org/u/stevengj)
#### Post date: [January 7, 2017, 4:19pm UTC](https://discourse.julialang.org/t/unzip-a-vector-of-pairs/1346/3 "2017-01-07T16:19:04Z")
> [@Tamas\_Papp](#):
>
> Given a Vector of Pairs, what’s an idiomatic way of getting a vector of first and second elements in each Pair?
`first.(x)` and `last.(x)` works pretty well and is terse.
---
### Author:  [@dpsanders](https://discourse.julialang.org/u/dpsanders)
#### Post date: [January 7, 2017, 4:20pm UTC](https://discourse.julialang.org/t/unzip-a-vector-of-pairs/1346/4 "2017-01-07T16:20:38Z")
One possibility is
```julia
julia> [first(p) for p in x]
5-element Array{Int64,1}:
1
2
3
4
5
julia> [last(p) for p in x]
5-element Array{Int64,1}:
2
4
6
8
10
```
EDIT:
Which can be written as `map(first, x)` and `map(last, x)`
I do agree that it is counterintuitive / unfortunate that two loops through are required.