# Bounds Error for loop

**URL:** <https://discourse.julialang.org/t/bounds-error-for-loop/119503>\
**Category:** New to Julia\
**Tags:** question, error\
**Created:** [September 17, 2024, 2:08pm UTC](https://discourse.julialang.org/t/bounds-error-for-loop/119503 "2024-09-17T14:08:23Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Anika\_Tarannum](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/anika_tarannum/32/212011_2.png) [@Anika\_Tarannum](https://discourse.julialang.org/u/Anika_Tarannum)\
**Post date:** [September 17, 2024, 2:08pm UTC](https://discourse.julialang.org/t/bounds-error-for-loop/119503/1 "2024-09-17T14:08:23Z")

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I was trying to run the code but in this block I am getting bounds error

for j in 1:5  
@constraint(model, sum(costs[i][j] \* x[i] for i in 1:14) \<= budgets[j])  
end

---

<div class="post-metadata">

**Author:** ![kapple](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/kapple/32/218915_2.png) [@kapple](https://discourse.julialang.org/u/kapple)\
**Post date:** [September 17, 2024, 2:14pm UTC](https://discourse.julialang.org/t/bounds-error-for-loop/119503/2 "2024-09-17T14:14:52Z")

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Instead of indexing `1:N`, use `eachindex` instead.

Does that fix things?

---

<div class="post-metadata">

**Author:** ![gdalle](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/gdalle/32/27854_2.png) [@gdalle](https://discourse.julialang.org/u/gdalle)\
**Post date:** [September 17, 2024, 3:13pm UTC](https://discourse.julialang.org/t/bounds-error-for-loop/119503/3 "2024-09-17T15:13:01Z")

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> [@Anika\_Tarannum](#):
>
> for j in 1:5  
> @constraint(model, sum(costs[i][j] \* x[i] for i in 1:14) \<= budgets[j])  
> end

More precisely, this might look like

```julia
for j in eachindex(budgets, first(costs))
    @constraint(
        model, sum(costs[i][j] * x[i] for i in eachindex(costs, x)) <= budgets[j]
    )
end

```

But maybe `costs` would be expressed more naturally as a matrix?