# Empty a queue
**URL:** https://discourse.julialang.org/t/empty-a-queue/36991
**Category:** General Usage
**Created:** [April 3, 2020, 10:19pm UTC](https://discourse.julialang.org/t/empty-a-queue/36991 "2020-04-03T22:19:31Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@lewis](https://discourse.julialang.org/u/lewis)
#### Post date: [April 3, 2020, 10:19pm UTC](https://discourse.julialang.org/t/empty-a-queue/36991/1 "2020-04-03T22:19:31Z")
Apparently, there is no way to empty! a queue.
Doc for DataStructures.jl shows an empty! method for a stack, but not for a queue.
It is quite difficult to tell what sort of beast a queue is since it wraps dequeue.
When I display my queue in the REPL, the beginning looks like this:
```julia
Queue{NamedTuple}(Deque
```
What follows is an array (well, a vector) of the NamedTuples that have been enqueued.
The appears to get no way to get at that array.
What to do to empty it?
To move on, I switched to a vector as I don’t care about all the fancy semantics. It works.
---
### Author:  [@stevengj](https://discourse.julialang.org/u/stevengj)
#### Post date: [April 3, 2020, 10:31pm UTC](https://discourse.julialang.org/t/empty-a-queue/36991/2 "2020-04-03T22:31:47Z")
> [@lewis](#):
>
> The appears to get no way to get at that array.
You can iterate over it, so `collect(queue)` works to get a copy of the queue as an array.
Normally, you don’t want to poke around in the internals of some other package’s data structure.
> [@lewis](#):
>
> What to do to empty it?
`empty!(queue)` works.
> [@lewis](#):
>
> To move on, I switched to a vector as I don’t care about all the fancy semantics.
If you don’t need queue semantics, you definitely shouldn’t use a queue data structure.
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### Author:  [@pixel27](https://discourse.julialang.org/u/pixel27)
#### Post date: [April 3, 2020, 10:37pm UTC](https://discourse.julialang.org/t/empty-a-queue/36991/3 "2020-04-03T22:37:56Z")
`empty!` is definitively defined for a Queue object:
>
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### Author:  [@lewis](https://discourse.julialang.org/u/lewis)
#### Post date: [April 3, 2020, 11:27pm UTC](https://discourse.julialang.org/t/empty-a-queue/36991/4 "2020-04-03T23:27:19Z")
I had a function for empty!(df::DataFrame). This blocked the use of empty! from DataStructures. Should I have done import Base.empty! ?
Just asking. The array is adequate to the purpose.
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### Author:  [@pixel27](https://discourse.julialang.org/u/pixel27)
#### Post date: [April 4, 2020, 12:21am UTC](https://discourse.julialang.org/t/empty-a-queue/36991/5 "2020-04-04T00:21:59Z")
> [@lewis](#):
>
> Should I have done import Base.empty! ?
I believe so. If you create a custom empty! for your data type then I believe can can do `function Base.empty!()` to ensure you don’t hide the others.
---
### Author:  [@stevengj](https://discourse.julialang.org/u/stevengj)
#### Post date: [April 4, 2020, 1:39am UTC](https://discourse.julialang.org/t/empty-a-queue/36991/6 "2020-04-04T01:39:55Z")
> [@lewis](#):
>
> I had a function for empty!(df::DataFrame). This blocked the use of empty! from DataStructures. Should I have done import Base.empty! ?
No, because defining your own `Base.empty!(df::DataFrame)` would be [type piracy](https://docs.julialang.org/en/v1/manual/style-guide/index.html#Avoid-type-piracy-1), and could easily conflict e.g. if the `DataFrames` package decides to implement `Base.empty!`.
Either call your function something else, or call `Base.empty!(queue)` when you want to use the standard `empty!` function.