For loop variable initialisation from a list

Question

Groovy allows unfolding lists in assignment, as in:

(x, y) = [1, 2]

So I assumed something similar would work in a for loop, as in:

list = [[1, 2], [2, 4], [3, 6]]
for ((elm1, elm2) in list) {...}

Which turns out to be a syntax error. Is this style not possible or is there some trick to it I'm missing?

Opal · Accepted Answer · 2016-01-16 07:18:49Z

3

I guess it won't work with the for loop (or I definitely don't know the syntax), however a two-argument closure can be used to iterate such a List, unfold the tuples:

def list = [[1, 2], [2, 4], [3, 6]]
assert list.collect { a, b -> a + b } == [3, 6, 9, ]

answered Jan 16, 2016 at 7:18

Opal

85.6k29 gold badges201 silver badges220 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

For loop variable initialisation from a list

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related