In dart,How to remove element in the NestedList - flutter

Question

Element not removed from the List. pls tell me how could i remove the element in the list
void main() {
List data=[['apple',1],['banana',5]];
data.remove(['apple',1]);
print(data);
}

Answer 1

Instead of defining dynamic objects like ['apple', 1]. Declare a class for it, and tell the program how those instances should be compared such as
class Fruit {
final String name;
final int index;
Fruit(this.index, this.name);
#override
int get hashCode => name.hashCode + index.hashCode * 7;
}
and then use it like;
void main() {
List data=[Fruit('apple', 1), Fruit('banana', 5),];
data.remove(['apple',1]);
print(data);
}

Answer 2

It's not very recommended to use List<dynamic> everywhere in dart. Tolga Kartal's answer gives a better practice.
Bur for your case, if you do not want to refactor your code, you can first find where ['apple', 1] is and then delete it from data.
void main() {
List data=[['apple',1],['banana',5]];
dynamic targetElement = data.firstWhere(
(element) => element[0]=='apple' && element[1]==1,
orElse: () => null);
if (targetElement != null)
data.remove(targetElement);
print(data);
}
The reason why you can't directly use data.remove(['apple', 1]) is that every time you use ['apple', 1], what you're actually doing is declaring a new List object. Although both ['apple', 1] have exactly same elements, their addresses in memory are different. To be more specific, they have different hash codes.
void main() {
List<dynamic> itemA = ['apple', 1];
List<dynamic> itemB = ['apple', 1];
print('hashcode of itemA and itemB');
print('itemA: ${itemA.hashCode}, itemB: ${itemB.hashCode}');
// <<< itemA: 397807318, itemB: 278500865
print('verify if they have same elements inside');
print('itemA[0] == itemB[0]:${itemA[0] == itemB[0]}, itemA[1] == itemB[1]:${itemA[1] == itemB[1]}');
// <<< itemA[0] == itemB[0]:true, itemA[1] == itemB[1]:true
print('check if itemA and itemB are same');
print('itemA == itemB: ${itemA == itemB}');
// <<< itemA == itemB: false
print('A case to show why they are different');
itemA.add('Hello');
itemB.add('World');
print('itemA: $itemA');
// <<< itemA: [apple, 1, Hello]
print('itemB: $itemB');
// <<< itemB: [apple, 1, World]
}
Hope this explanation helps.

Answer 3

Just replace ['apple',1] to index, In this case 0
void main() {
List data=[['apple',1],['banana',5]];
data.remove(0);
print(data);
}
Hope it work