Clever Geek Handbook

Changing the values ​​of elements of composite types in an array

In Julia (0.3.0-rc1), when I have an fill

array with composite type instances and update a member of one instance, all the array instances are updated. Is this the intended behavior, and if so, how do I change the value of only one element in the array?

The code in question:

type Foo
    x :: Int
    y :: Int
end

arr = fill(Foo(2, 4), 3)
arr[2].x = 5

I expect [Foo(2, 4), Foo(5, 4), Foo(2, 4)]

, but I get instead [Foo(5, 4), Foo(5, 4), Foo(5, 4)]

. What am I doing wrong? Should I always update the whole element like in arr[2] = Foo(5, 4)

(which gives the expected results)? TIA.

+3


source to share


1 answer


You have created one instance Foo

and populated an array with references to that one instance.



You will probably need arr = [Foo(2,4) for i in 1:3]

one that will create a new copy Foo(2,4)

for each index.

+3


source






More articles:


All Articles