Remove Empty or false Values from a List in Flutter

If you need to remove empty, null, or false values in a List, you may use the code snippets provided in this post to remove them from the list.

The first example uses the built-in List.removeWhere() method to remove all empty, null, or false values from the list. This method takes a predicate as an argument and calls it for each element in the list. If the predicate returns true, the element is removed from the list.

final list = ['', 'Sample','', 100, null, 32, 999999999, false];
list.removeWhere((item) => [null, false, ''].contains(item));
//output: ['Sample', 100, 32, 999999999]

final list = ['', 'Samsung','', 'Apple'];
list.removeWhere((item) => item.isEmpty);
//output: ['Samsung', 'Apple']

The second example uses the built-in List.retainWhere() method to remove all non-empty, non-null, truthy values from the list. This method also takes a predicate as an argument and calls it for each element in the list. If the predicate returns true, the element is retained in the list; if it returns false, the element is removed from the list. These methods can be used to filter out any values you don’t want in your list.

final list = ['', 'Samsung','', 'Apple'];
list.retainWhere((item) => item != '');
//output: ['Samsung', 'Apple']

Or you can use the good old loop approach to remove all the empty, false, and unwanted values from the list.

final list = ['', 'Sample','', 100, null, 32, 999999999, false];
List result = [];

for (var item in list) {
  if (!["", null, false, 0].contains(item)) {
    result.add(car);
  }
}