comparing two string lists and check if they have at least one same string

Question

I'm trying to compare two String list with each other and check if at least the have one exact same string or not ..

For example:

List<String> list1 = ['1','2','3','4'];

List<String> list2 = ['1','5','6','7'];

In this case I will do action cause both have same string which is 1, and it could be more than one exact same string and the action will be the same.

But if they don't have any similar strings then I will do another action.

How can I do something like this?

@MatthewPage of course i know! but this doesn't work with looping :) — lamatat, Jan 28 '19 at 12:22

score 19 · Answer 1 · answered Jan 28 '19 at 12:14

19

You can do it with any() and contains() method:

if (list1.any((item) => list2.contains(item))) {
    // Lists have at least one common element
} else {
    // Lists DON'T have any common element
}

answered Jan 28 '19 at 12:14

Albert221

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Thank you so much! – lamatat Jan 28 '19 at 12:21
@lamatat if you found an answer helpful and it resolves your issue, please accept the answer :) – Albert221 Jan 28 '19 at 21:00
both answers are helpful and working and answered the same time .. i don't know to accept which so i uovoted both lol – lamatat Jan 29 '19 at 06:22

score 9 · Answer 2 · answered Jan 28 '19 at 12:13

9

Set has an intersection that does that:

list1.toSet().intersection(list2.toSet()).length > 0

answered Jan 28 '19 at 12:13

Günter Zöchbauer

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https://stackoverflow.com/questions/10404516/how-can-i-compare-lists-for-equality-in-dart mentions some other handy features to compare lists or iterables (not directly related to the question though) – Günter Zöchbauer Jan 28 '19 at 12:22
2

Instead of converting both to sets, you can als just do `list1.any(list2.toSet().contains)`. – lrn Jan 29 '19 at 06:37

score 0 · Answer 3 · answered Nov 30 '22 at 14:45

0

A shorter version:

bool hasCommonElement = list1.any(list2.contains);

answered Nov 30 '22 at 14:45

iDecode

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comparing two string lists and check if they have at least one same string

3 Answers3