# Strange error

**URL:** <https://discourse.julialang.org/t/strange-error/78851>\
**Category:** General Usage\
**Created:** [April 1, 2022, 8:03am UTC](https://discourse.julialang.org/t/strange-error/78851 "2022-04-01T08:03:36Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![RogerP](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/rogerp/32/17496_2.png) [@RogerP](https://discourse.julialang.org/u/RogerP)\
**Post date:** [April 1, 2022, 8:03am UTC](https://discourse.julialang.org/t/strange-error/78851/1 "2022-04-01T08:03:36Z")

</div>

Could someone explain to me what is happening here? Try running mwe1() and then mwe2()

```julia
function mwe1()
        initfloat::Vector{Float64} = zeros(1)
        Φ::Vector{Float64} = initfloat
        Θ̇::Vector{Float64} = initfloat
        for i = 1:1
            Θ̇[i] = 2.0
            println("Theta dot = ", Θ̇[i])
            Φ[i] = 0.1i #Float x Int
            println("Theta dot = ", Θ̇[i])
        end
    end
    
function mwe2()
    i = 1
    Θ̇ = 2.0
    println("Theta dot = ", Θ̇)
    Φ = 0.1i #Float x Int
    println("Theta dot = ", Θ̇)
end

```

Many thanks!

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<div class="post-metadata">

**Author:** ![RogerP](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/rogerp/32/17496_2.png) [@RogerP](https://discourse.julialang.org/u/RogerP)\
**Post date:** [April 1, 2022, 8:06am UTC](https://discourse.julialang.org/t/strange-error/78851/2 "2022-04-01T08:06:21Z")

</div>

BTW:

```julia
julia> versioninfo()
Julia Version 1.7.2
Commit bf53498635 (2022-02-06 15:21 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
  CPU: Intel(R) Core(TM) i7-10750H CPU @ 2.60GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-12.0.1 (ORCJIT, skylake)
Environment:
  JULIA_NUM_THREADS = 6
  JULIA_EDITOR = code
  JULIA_PROJECT = /home/rpowell/APCSv0.1.2/apcs.jl/

```

---

<div class="post-metadata">

**Author:** ![stepanzh](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/stepanzh/32/34851_2.png) [@stepanzh](https://discourse.julialang.org/u/stepanzh)\
**Post date:** [April 1, 2022, 8:11am UTC](https://discourse.julialang.org/t/strange-error/78851/3 "2022-04-01T08:11:38Z")

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In `mwe1`, `Φ` and `Θ̇` reference to the same array `initfloat`.

```julia
function mwe1()
    initfloat::Vector{Float64} = zeros(1)
    Φ::Vector{Float64} = initfloat # it is not a copy, it is a new reference
    Θ̇::Vector{Float64} = initfloat # it is too

    @show Φ === Θ̇ # true
    ...
end

```

---

<div class="post-metadata">

**Author:** ![RogerP](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/rogerp/32/17496_2.png) [@RogerP](https://discourse.julialang.org/u/RogerP)\
**Post date:** [April 1, 2022, 8:27am UTC](https://discourse.julialang.org/t/strange-error/78851/4 "2022-04-01T08:27:48Z")

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Many thanks! I completely forgot about how that works. Silly me!