# For loop not working as expected
**URL:** https://discourse.julialang.org/t/for-loop-not-working-as-expected/8532
**Category:** General Usage
**Tags:** question
**Created:** [January 22, 2018, 9:14pm UTC](https://discourse.julialang.org/t/for-loop-not-working-as-expected/8532 "2018-01-22T21:14:38Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@Yifan\_Liu](https://discourse.julialang.org/u/Yifan_Liu)
#### Post date: [January 22, 2018, 9:14pm UTC](https://discourse.julialang.org/t/for-loop-not-working-as-expected/8532/1 "2018-01-22T21:14:38Z")
My code is as below:
```julia
using FinancialToolbox
r=0.01*0.303
q=0.01*0.202
s=0.20
T=0.50
b=r-q
S=1500
K=1000:5:2000
for i = 1:length(K)
res1 = zeros(length(K))
res1[i] = blsprice(S, K[i], r, T, s, q)
end
```
It seems the res1 I got is still zero arrays, and I am not sure what could be the issue.
---
### Author:  [@Seif\_Shebl](https://discourse.julialang.org/u/Seif_Shebl)
#### Post date: [January 22, 2018, 9:19pm UTC](https://discourse.julialang.org/t/for-loop-not-working-as-expected/8532/2 "2018-01-22T21:19:33Z")
> [@Yifan\_Liu](#):
>
> res1 = zeros(length(K))
You are using `res1 = zeros(length(K))` at each loop iteration, what do you expect at the nth iteration other than an all-zeros array with only `res1[n]` having nonzero value?
Move this line `res1 = zeros(length(K))` before the for-loop.
```
⋮
res1 = zeros(length(K))
for i = 1:length(K)
res1[i] = blsprice(S, K[i], r, T, s, q)
end
```
Outputs:
```
julia> res1
201-element Array{Float64,1}:
500.103
495.124
490.147
485.171
480.197
475.225
470.255
465.288
460.323
455.362
450.403
445.447
440.495
⋮
3.15828
3.0192
2.88581
2.7579
2.63527
2.51772
2.40506
2.29711
2.19369
2.09462
1.99974
1.90889
```
---
### Author:  [@Yifan\_Liu](https://discourse.julialang.org/u/Yifan_Liu)
#### Post date: [January 22, 2018, 9:52pm UTC](https://discourse.julialang.org/t/for-loop-not-working-as-expected/8532/3 "2018-01-22T21:52:20Z")
HAHA, thanks so much! By the way, do you know if the blsprice function has a call/put parameter input? I could not find any documentation about the financialtoolbox package.
---
### Author:  [@Seif\_Shebl](https://discourse.julialang.org/u/Seif_Shebl)
#### Post date: [January 22, 2018, 10:15pm UTC](https://discourse.julialang.org/t/for-loop-not-working-as-expected/8532/4 "2018-01-22T22:15:10Z")
I didn’t use this package my self, but you can see the implementation of this function at [this line in the source of FinancialToolbox.jl](https://github.com/rcalxrc08/FinancialToolbox.jl/blob/9a6f86fe3b4f14d884183d194efbd564ad079ef3/src/financial.jl#L31).
---
### Author:  [@Yifan\_Liu](https://discourse.julialang.org/u/Yifan_Liu)
#### Post date: [January 22, 2018, 10:43pm UTC](https://discourse.julialang.org/t/for-loop-not-working-as-expected/8532/5 "2018-01-22T22:43:03Z")
I use this code
`blsprice(10.0,10.0,0.01,2.0,0.2,0.01, FlagIsCall = false)`
but got the error message
ERROR: function blsprice does not accept keyword arguments
---
### Author:  [@Non-Contradiction](https://discourse.julialang.org/u/Non-Contradiction)
#### Post date: [January 22, 2018, 10:55pm UTC](https://discourse.julialang.org/t/for-loop-not-working-as-expected/8532/6 "2018-01-22T22:55:16Z")
`FlagIsCall = false` is keyword argument.
Following the error message, you should use `blsprice(10.0,10.0,0.01,2.0,0.2,0.01, false)` instead.
For further information on keyword argument, see: [https://docs.julialang.org/en/stable/manual/functions/#Keyword-Arguments-1](https://docs.julialang.org/en/stable/manual/functions/#Keyword-Arguments-1)
---
### Author:  [@NaOH](https://discourse.julialang.org/u/NaOH)
#### Post date: [January 22, 2018, 11:21pm UTC](https://discourse.julialang.org/t/for-loop-not-working-as-expected/8532/7 "2018-01-22T23:21:35Z")
`FlagIsCall` is **not** a keyword argument, it is an optional positional argument!
```julia
julia> foo(positional, optional = true) = (positional, optional)
foo (generic function with 2 methods)
julia> foo(false)
(false, true)
julia> foo(false, false)
(false, false)
julia> foo(false, optional = false)
ERROR: function foo does not accept keyword arguments
Stacktrace:
[1] kwfunc(::Any) at ./boot.jl:237
```
Keyword arguments are declared after a semicalon `;` in the parameter list:
```julia
julia> bar(positional, optional = true; keyword = 42) = (positional, optional, keyword)
bar (generic function with 2 methods)
julia> bar(false)
(false, true, 42)
julia> bar(false, false)
(false, false, 42)
julia> bar(false, false, keyword = 7)
(false, false, 7)
```