# How can i convert number string array to int array
**URL:** https://discourse.julialang.org/t/how-can-i-convert-number-string-array-to-int-array/32536
**Category:** General Usage
**Created:** [December 21, 2019, 4:42am UTC](https://discourse.julialang.org/t/how-can-i-convert-number-string-array-to-int-array/32536 "2019-12-21T04:42:14Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@imrankhan\_juliaLang](https://discourse.julialang.org/u/imrankhan_juliaLang)
#### Post date: [December 21, 2019, 4:42am UTC](https://discourse.julialang.org/t/how-can-i-convert-number-string-array-to-int-array/32536/1 "2019-12-21T04:42:14Z")
Need help to convert string number array to int array
**Like**
[“0”, “1”, “0”, “1”, “0”, “1”, “1”, “1”] **To** [0, 1, 0, 1, 0, 1, 1, 1]
**NB:** Without use this code
`[parse(Int, x) for x in array]`
because this method is too slow in big array **[array size about 1 million +]**
---
### Author:  [@baggepinnen](https://discourse.julialang.org/u/baggepinnen)
#### Post date: [December 21, 2019, 5:51am UTC](https://discourse.julialang.org/t/how-can-i-convert-number-string-array-to-int-array/32536/2 "2019-12-21T05:51:08Z")
You could potentially convert it to a categorical array first.
---
### Author:  [@Syx\_Pek](https://discourse.julialang.org/u/Syx_Pek)
#### Post date: [December 21, 2019, 7:27am UTC](https://discourse.julialang.org/t/how-can-i-convert-number-string-array-to-int-array/32536/3 "2019-12-21T07:27:03Z")
Is it really a problem?
```julia
julia> A = [string(rand(1:1000)) for _ in 1:1_000_000];
julia> @btime parse.(Int, $A);
27.091 ms (2 allocations: 7.63 MiB)
```
---
### Author:  [@DNF](https://discourse.julialang.org/u/DNF)
#### Post date: [December 21, 2019, 9:03am UTC](https://discourse.julialang.org/t/how-can-i-convert-number-string-array-to-int-array/32536/4 "2019-12-21T09:03:49Z")
It seems like these two methods are equally fast:
```julia
julia> a = rand(("0", "1"), 10^6);
julia> @btime [parse(Int, x) for x in $a];
36.087 ms (3 allocations: 7.63 MiB)
julia> @btime parse.(Int, $a);
35.576 ms (2 allocations: 7.63 MiB)
```
It seems pretty fast to me.
If, however, the inputs are `Char`s instead of `String`s, it can get faster:
```julia
julia> c = rand('0':'1', 10^6);
julia> @btime parse.(Int, $c);
8.302 ms (2 allocations: 7.63 MiB)
```
or even
```julia
julia> @btime Int.($c) .- 48;
2.241 ms (2 allocations: 7.63 MiB)
```
Here’s another one, if `Int8` is ok:
```julia
julia> @btime Int8.($c) .- Int8(48);
784.793 μs (2 allocations: 976.70 KiB)
```
---
### Author:  [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)
#### Post date: [December 21, 2019, 10:50am UTC](https://discourse.julialang.org/t/how-can-i-convert-number-string-array-to-int-array/32536/5 "2019-12-21T10:50:14Z")
If you don’t need to validate inputs and these are the only two options, something like
```julia
parse01(str) = str == "1" ? 1 : 0
```
could work, eg
```julia
julia> @btime parse01.($a);
4.704 ms (2 allocations: 7.63 MiB)
```
but, like the others contributing to this topic, I wonder if this is really the bottleneck in your code. I would go with `parse(Int, ...)` as the cost is trivial in any case, and it is robust and readable.