Variable scope in for loop

General Usage
1

Hi,
Please see the following code:

for i = 1:2
    a = 7
    for i = 3
        a = 9
    end
    @show a
    @show i
end

which has the output:

a = 9
i = 1
a = 9
i = 2

My question is, why is the value of “i” not modified by the inner for loop? I think its value should be modified just like what happened to variable “a”.

I’m using Julia 1.3.1

Thank you!

2

The relevant docs section is For Loops and Comprehensions.

What you want is:

for i = 1:2
    a = 7
    for outer i = 3
        a = 9
    end
    @show a
    @show i
end

Which gives:

a = 9
i = 3
a = 9
i = 3
1 Like
3

Thank you! Very helpful!

1 Like