Re^4: Array wierdness -- initialize AoA

Hello,

you can also initialize an ArrayOfArrays setting default values using x (repetition operator in list context) like in: @aoa = ([( 1 ) x 3]) x 3

PS I evidently need more coffeine this morning.. see below

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Re^5: Array wierdness -- initialize AoA by hv (Prior) on Apr 26, 2022 at 09:13 UTC
That's usually not what you want: that'll give you three copies of the same arrayref, so if you later modify an element in one row it'll modify it in all rows: `% perl -wle '@aoa = ([(1) x 3]) x 3; $aoa[1][2] = 3; print "@$_" for @ +aoa' 1 1 3 1 1 3 1 1 3` [download] If you want each element to be independent, a typical approach is to pass it through `map`: `% perl -wle '@aoa = map [(1) x 3], 1..3; $aoa[1][2] = 3; print "@$_" f +or @aoa' 1 1 1 1 1 3 1 1 1` [download]	[reply] [d/l] [select]

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Re^5: Array wierdness -- initialize AoA
by hv (Prior) on Apr 26, 2022 at 09:13 UTC

That's usually not what you want: that'll give you three copies of the same arrayref, so if you later modify an element in one row it'll modify it in all rows:

% perl -wle '@aoa = ([(1) x 3]) x 3; $aoa[1][2] = 3; print "@$_" for @
+aoa'
1 1 3
1 1 3
1 1 3
[download]

If you want each element to be independent, a typical approach is to pass it through map:

% perl -wle '@aoa = map [(1) x 3], 1..3; $aoa[1][2] = 3; print "@$_" f
+or @aoa'
1 1 1
1 1 3
1 1 1
[download]

[reply]
[d/l]
[select]