Loop over multiple arrays simultaneously: Difference between revisions

=={{header|Picat}}==

Picat has a built-in zip/n and only works with lists (not arrays). It returns an array tuple ({A,B,C}) and not a list ([A,B,C]), which is a typical gotcha.

For this task, a foreach loop and list comprenhension are shown.

If the lists/arrays are of uneven lengths, then the elements in the longer arrays are skipped.

<lang Picat>import util.

go =>

L1 = ["a","b","c"],

L2 = ["A","B","C"],

L3 = ["1","2","3"],

println("foreach loop:"),

foreach({A,B,C} in zip(L1,L2,L3))

println([A,B,C].join(''))

end,

nl,

println("list comprehension/n:"),

println( [[A,B,C].join('') : {A,B,C} in zip(L1,L2,L3)].join("\n")),

nl,

% With uneven lengths the last elements in the longer lists are skipped.

println("Uneven lengths:"),

L4 = ["P","Q","R","S"], % longer than the other

foreach({A,B,C,D} in zip(L1,L2,L3,L4))

println([A,B,C,D].join(''))

end,

nl.</lang>

Output:

<pre>foreach loop:

aA1

bB2

cC3

list comprehension/n:

aA1

bB2

cC3

Uneven lengths:

aA1P

bB2Q

cC3R</pre>