# Updating DistributedArray using the primitive DArray constructor

**URL:** https://discourse.julialang.org/t/updating-distributedarray-using-the-primitive-darray-constructor/46301
**Category:** New to Julia
**Tags:** question, distributed
**Created:** [September 9, 2020, 2:31am UTC](https://discourse.julialang.org/t/updating-distributedarray-using-the-primitive-darray-constructor/46301 "2020-09-09T02:31:02Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![mkarikom](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mkarikom/32/7096_2.png) [@mkarikom](https://discourse.julialang.org/u/mkarikom)
#### Post date: [September 9, 2020, 2:31am UTC](https://discourse.julialang.org/t/updating-distributedarray-using-the-primitive-darray-constructor/46301/1 "2020-09-09T02:31:02Z")

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The following syntax is [demonstrated in the manual](https://juliaparallel.github.io/DistributedArrays.jl/stable/#Distributed-Array-Operations-1):

```julia
DArray(size(d),procs(d)) do I
...
end

```

I haven’t seen a loop like this before. What is `I`?

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<div class="post-metadata">

### Author: ![bjarthur](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bjarthur/32/9638_2.png) [@bjarthur](https://discourse.julialang.org/u/bjarthur)
#### Post date: [September 10, 2020, 11:55am UTC](https://discourse.julialang.org/t/updating-distributedarray-using-the-primitive-darray-constructor/46301/2 "2020-09-10T11:55:36Z")

</div>

`I` is the input argument to the following `do` block. see [Functions · The Julia Language](https://docs.julialang.org/en/v1/manual/functions/#Do-Block-Syntax-for-Function-Arguments)