CODEWITHSUNDEEP
listflutterdartcontains
katre
katre

Reputation: 313

how can I find a list contains in any element another list in flutter?

var firstList= [1,2,3,4,5];
var secondList= [3,5];

// compare result : 3,5
// return true

var firstList= [1,2,3,4,5];
var secondList= [6,7,8];

// compare result : null
// return false

How can I compare elements the two lists? If there is matching data in the two lists, return true. if there is no match, return false

Upvotes: 7

Views: 17029

Answers (6)

CoderBlue
CoderBlue

Reputation: 965

Function to Test If One List Has Elements of Another List

Just following up on Josteve's answer - this returns a bool as requested in the question rather than a string as Josteve's snippet shows:

void main() {
  
var firstList= [1,2,3,4,5];
var secondList= [3,5];
var thirdList= [9,10];

  
 //There IS an intersection
  
print("Second List: ${isIntersect(secondList, firstList)}");

  //There is NO intersection
  
print("Third List: ${isIntersect(thirdList, firstList)}");
  
}


bool isIntersect(List listOne, List listTwo) {
  return listOne.toSet().intersection(listTwo.toSet()).isNotEmpty;
}

Demo is also on Dart Pad

Upvotes: 0

Derek Davidson
Derek Davidson

Reputation: 3

I found this works

bool bTest2 = lstPlayerIDPieceLocationPointID
        .any((element) => lstFoundPoints.contains(element));
    print('bTest2 any..contains: $bTest2');

Always finding if any item in 1 list is also in the other list. I did not care what is was, I just wanted to know if there is a match

Upvotes: 0

Javad Moradi
Javad Moradi

Reputation: 994

there is plenty of ways to do it, you could use every() and contains() methods to achieve this

this is how I would do it:

  if (secondList.every((item) => firstList.contains(item))) {
    return true;
  } else {
    return false;
  }

Upvotes: 18

Dmitry Bubnenkov
Dmitry Bubnenkov

Reputation: 9859

Next solution is not perfect, but maybe helpful for someone:

void main() {
  var list = ["aa", "bb", "cc"];
  for (var el in ['abc', 'aaa', 'bb', 'hmbb', 'afg', 'hhcc']) {
    bool isContains = list.any((e) => el.contains(e));
    if(isContains) {
      print(el);
    }
  }
}

Output:

aaa
bb
hmbb
hhcc

Upvotes: 2

awaik
awaik

Reputation: 12287

And one more quick way just to check true or false

var firstList = [2, 2, 2, 3];
var secondList = [3, 3, 3];
check(int value) => firstList.contains(value);
bool res = secondList.any(check); // returns true

Upvotes: 5

Josteve Adekanbi
Josteve Adekanbi

Reputation: 12673

This should help you...

var firstList = [2, 2, 2, 3];
var secondList = [3, 3, 3];

var firstListSet = firstList.toSet();
var secondListSet = secondList.toSet();

print(firstListSet.intersection(secondListSet));

Upvotes: 20

Related Questions