# The input number of one function
**URL:** https://discourse.julialang.org/t/the-input-number-of-one-function/15449
**Category:** New to Julia
**Tags:** matlab
**Created:** [September 25, 2018, 4:42am UTC](https://discourse.julialang.org/t/the-input-number-of-one-function/15449 "2018-09-25T04:42:49Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@sysk\_msk](https://discourse.julialang.org/u/sysk_msk)
#### Post date: [September 25, 2018, 4:42am UTC](https://discourse.julialang.org/t/the-input-number-of-one-function/15449/1 "2018-09-25T04:42:49Z")
I want to let Julia to known the number of parameters which I have provided in one function. Like nargin in MATLAB. What should I do?
---
### Author:  [@stillyslalom](https://discourse.julialang.org/u/stillyslalom)
#### Post date: [September 25, 2018, 5:02am UTC](https://discourse.julialang.org/t/the-input-number-of-one-function/15449/2 "2018-09-25T05:02:08Z")
It’s hard to imagine a case where `nargin` would be a better choice than just using Julia’s multiple dispatch and keyword arguments. Can you provide a short pseudocode example of what you’re trying to do?
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### Author:  [@mauro3](https://discourse.julialang.org/u/mauro3)
#### Post date: [September 25, 2018, 5:19am UTC](https://discourse.julialang.org/t/the-input-number-of-one-function/15449/3 "2018-09-25T05:19:51Z")
I second @stillyslalom. However it could be done with
```julia
function f(args...)
nargin = length(args)
# now what?
end
```
---
### Author:  [@sysk\_msk](https://discourse.julialang.org/u/sysk_msk)
#### Post date: [September 25, 2018, 7:14am UTC](https://discourse.julialang.org/t/the-input-number-of-one-function/15449/4 "2018-09-25T07:14:43Z")
For example,I have such a function:
```julia
function A(file1,file2,file3,img1,img2,img3,...)
# I need to known how many pictures and files it should be offered.
if (nargin < 6)
file1->img1
file1<-img2
end
if (nargin <10)
file1->img1
file1<-img2
file2->img3
file2<-img4
end
...
end
```
---
### Author:  [@mauro3](https://discourse.julialang.org/u/mauro3)
#### Post date: [September 25, 2018, 7:19am UTC](https://discourse.julialang.org/t/the-input-number-of-one-function/15449/5 "2018-09-25T07:19:19Z")
I think you should
```julia
function a(files, images)
for i=1:2:length(files)
...
end
end
```
if you really want to pass them in a separate arguments
```julia
function a(args...)
files = args[1:2:end÷2]
imgs = args[2:2:end÷2]
for i=1:length(files)
..
end
end
```
---
### Author:  [@sysk\_msk](https://discourse.julialang.org/u/sysk_msk)
#### Post date: [September 25, 2018, 7:24am UTC](https://discourse.julialang.org/t/the-input-number-of-one-function/15449/6 "2018-09-25T07:24:01Z")
Thank you very much.