# Weird behavior in Complex Numbers

**URL:** <https://discourse.julialang.org/t/weird-behavior-in-complex-numbers/21940>\
**Category:** New to Julia\
**Tags:** complex-numbers\
**Created:** [March 16, 2019, 2:37pm UTC](https://discourse.julialang.org/t/weird-behavior-in-complex-numbers/21940 "2019-03-16T14:37:15Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![karthik](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/karthik/32/7450_2.png) [@karthik](https://discourse.julialang.org/u/karthik)\
**Post date:** [March 16, 2019, 2:37pm UTC](https://discourse.julialang.org/t/weird-behavior-in-complex-numbers/21940/1 "2019-03-16T14:37:15Z")

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Hello, i am getting this behavior:

```
julia> a = 1.5 + 3//4im
1.5 - 0.75im

```

What I expected was:

```
julia> a = 1.5 + 3//4im
1.5 + 0.75im

```

Can any one tell me why?

---

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**Author:** ![Richard\_Dennis](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/richard_dennis/32/7451_2.png) [@Richard\_Dennis](https://discourse.julialang.org/u/Richard_Dennis)\
**Post date:** [March 16, 2019, 2:42pm UTC](https://discourse.julialang.org/t/weird-behavior-in-complex-numbers/21940/2 "2019-03-16T14:42:41Z")

</div>

try

julia\> a = 1.5 + (3//4)im

---

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**Author:** ![giordano](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/giordano/32/2166_2.png) [@giordano](https://discourse.julialang.org/u/giordano)\
**Post date:** [March 16, 2019, 2:56pm UTC](https://discourse.julialang.org/t/weird-behavior-in-complex-numbers/21940/3 "2019-03-16T14:56:27Z")

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> [@karthik](#):
>
> Can any one tell me why?

Multiplication by juxtaposition has higher precedence than `//`, so what you’re actually computing is `3//(4im)`. You can see how an expression is lowered for example with:

```julia
julia> Meta.@lower 3//4im
:($(Expr(:thunk, CodeInfo(
1 ─ %1 = 4im
│ %2 = 3 // %1
└── return %2
))))

```

---

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**Author:** ![improbable22](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/improbable22/32/5464_2.png) [@improbable22](https://discourse.julialang.org/u/improbable22)\
**Post date:** [March 16, 2019, 3:37pm UTC](https://discourse.julialang.org/t/weird-behavior-in-complex-numbers/21940/4 "2019-03-16T15:37:16Z")

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> [@giordano](#):
>
> Multiplication by juxtaposition has higher precedence than `//`

And by `/`, it turns out. So you can write this, which is nice to know!

```julia
julia> 1/2π == 1/(2π)
true

```

Also:

```julia
julia> 1/2*π == 0.5π
true

julia> 1/2big(π) == 1/(2*big(π))
true

```

---

<div class="post-metadata">

**Author:** ![karthik](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/karthik/32/7450_2.png) [@karthik](https://discourse.julialang.org/u/karthik)\
**Post date:** [March 16, 2019, 5:21pm UTC](https://discourse.julialang.org/t/weird-behavior-in-complex-numbers/21940/5 "2019-03-16T17:21:37Z")

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Thank you. I can sleep in peace today 🙂