How to Remove Element from List based on a Condition in Dart - Step by Step Examples

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How to Remove Element from List based on a Condition in Dart ?

Answer

To remove elements from a list based on a condition in Dart, you can use the `removeWhere` method.

✐ Examples

1 Remove Elements Greater Than a Threshold

In this example,

We create a list named numbers with some elements.
We specify the threshold value.
We use the removeWhere method along with a lambda function to remove elements greater than the threshold.
Finally, we print the modified list to standard output.

Dart Program

void main() {
  List<int> numbers = [1, 2, 3, 4, 5];
  int threshold = 3;
  numbers.removeWhere((num) => num > threshold);
  print('Modified list after removing elements greater than $threshold: $numbers');
}

Output

Modified list after removing elements greater than 3: [1, 2, 3]

2 Remove Elements Matching a Predicate

In this example,

We create a list named names with some elements.
We define a predicate function isLongName that returns true if the length of the string is greater than a specified value.
We use the removeWhere method along with the isLongName predicate to remove elements matching the predicate condition.
Finally, we print the modified list to standard output.

Dart Program

void main() {
  List<String> names = ['John', 'Alice', 'Michael', 'Emma'];
  int maxLength = 5;
  bool isLongName(String name) => name.length > maxLength;
  names.removeWhere((name) => isLongName(name));
  print('Modified list after removing long names: $names');
}

Output

Modified list after removing long names: [John, Alice, Emma]

Summary

In this tutorial, we learned How to Remove Element from List based on a Condition in Dart language with well detailed examples.

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