Question about global variable behavior

General Usage
2

  1. To format code wrap it between triple ticks:
    ```
    at the beginning and at the end
    ```

    Will look like this:

    at the beginning and at the end

  2. This is not aboout global variables. When you do An = A you are giving a new name (An) to the same object in memory as A. So when you modify one you modify the other one as well.

    You want to do:

    An = copy(A)

This behavior is mentioned for example in the second point of this list: Noteworthy Differences from other Languages · The Julia Language

By the way this works the same in python, maybe you were thinking Matlab?:


In [3]: a = [[1, 1, 1], [2, 2, 2]]

In [4]: a
Out[4]: [[1, 1, 1], [2, 2, 2]]

In [5]: a1 = a

In [6]: a1[1][1] = 5

In [7]: a1
Out[7]: [[1, 1, 1], [2, 5, 2]]

In [8]: a
Out[8]: [[1, 1, 1], [2, 5, 2]]
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