Shorthand for-loop to iterate through an array with both value and index

user_1364192 0
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Is there a convenient/shorthand way to iterate through a for loop on an array, getting both value and index?

Basic options:

i = 1
for file in ["foo.csv", "bar.csv"]
    ...
   i += 1
end

files = ["foo.csv", "bar.csv"]
for i in 1:length(files)
   files[i]
end
julia
1 Answers

Edit: As Matt B points out, pairs is simple and index-safe (if using an OffsetArray, named tuple, dictionary etc.):

for (i, file) in pairs(["foo.csv", "bar.csv"])
    ...
end

One option is enumerate:

for (i, file) in enumerate(["foo.csv", "bar.csv"])
    ...
end

but note that enumerate doesn't necessarily provide valid indices, since it's effectively zip(x, countfrom(1)) and would break for OffsetArrays.

Another that's index-safe, but requires files to be a variable:

files = ["foo.csv", "bar.csv"]
for (i, file) in zip(eachindex(files), files)
    ...
end
user_13641920
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