CODEWITHSUNDEEP
julia
Soumya
Soumya

Reputation: 95

What does // operator mean in Julia?

say I have this code:

a = 4//2

This returns me "2//1"

b = 4//3

This returns me "4//3"

I understand that it is returning the value of a and b in simplest form. But what then? I thought that this operator returns the value of division in integer form, taking away the reminder. But it does not seem this is what it is doing.

I actually have this code:

x=Fun(identity,0..4π)
d=domain(x)
B=[ldirichlet(d),lneumann(d),rneumann(d)]
D=Derivative(d)
κ = 0.33205733621519630   
u0 = (1//2) * κ * x^2

I wanted to know what (1//2) here is. From what I had thought earlier, this should have been equal to zero, but that is not what is required here. Can please someone clarify what is happening here and how does the // operator works?

Upvotes: 3

Views: 145

Answers (1)

Przemyslaw Szufel
Przemyslaw Szufel

Reputation: 42214

In Julia when you do not know something the first thing to do is to press ? to go to the help REPL mode represented by help?> prompt. After pressing ? type the command you are curious about:

help?> //
search: //

  //(num, den)

  Divide two integers or rational numbers, giving a Rational result.

  Examples
  ≡≡≡≡≡≡≡≡≡≡

  julia> 3 // 5
  3//5

  julia> (3 // 5) // (2 // 1)
  3//10

One more additional usefull way to check what is going on in Julia is to use dump:

julia> dump(2//4)
Rational{Int64}
  num: Int64 1
  den: Int64 2

Finally, following the comment by @DNF it is worth noting that there is the integer division operator ÷ (and a corresponding function div) that computes x/y, truncated to an integer.:

julia> 13 ÷ 4
3

Upvotes: 3

Related Questions