Dart – If All Elements in List satisfy given Condition

To check if all of the elements from a List satisfy a given test/condition in Dart, call every() method on this list and pass the test function as argument. every() method returns true if all the elements return true for given test function, or else it returns false if any of the elements returns false for given test function.

The test function must take the element as argument and return a boolean value.

Syntax

The syntax to call every() method on the List list with test function test passed as argument is

list.every(test)

Example

In this example, we take a list of integers, and check if all these integers are even numbers, using List.every() method. The test function is a lambda function that takes an integer and returns true if the integer is even number, or false if not.

main.dart

bool isEven(int n) => (n % 2 == 0);

void main() {
  var list = [2, 4, 8, 16, 32];
  var result = list.any(isEven);
  print('Are all even numbers :  $result');
}

Output

Are all even numbers :  true

Conclusion

In this Dart Tutorial, we learned how to check if all elements from the list satisfies given test function, with examples.