Finding the index of an object containing a matching element-CodePudding

I have a List of Objects in the file list.dart:

final itemList = [
  ItemData(uuid: 'one', score: '30', title: 'Title One', description: 'mock description'),
  ItemData(uuid: 'two', score: '10', title: 'Title Two', description: 'mock description'),
  ItemData(uuid: 'three', score: '20', title: 'Title Three', description: 'mock description'),
];

I am calling back UUID: 'one' to another widget in the file edit.dart

    return GestureDetector(
      onTap: (){
        currentItem = item.uuid; //currentItem declared in file edit.dart
        DisplayItem(); //callback function to edit.dart
      },
      child: Card(

My plan is to use the callback function to get the elements with the corresponding uuid. My problem is I can't figure out how to find the index of the object with the element equal to a given uuid. I've tried nesting indexOf() but get exponentially confused.

CodePudding user response：

So if I understand correctly, you have a list of items and you want to find the index of the first item that fulfils a condition (in this case the condition is that the items UUID value is equal to some value)

In order to do something like that, you can use the indexWhere method:

var targetUuid = 'one';

int itemIndex = itemList.indexWhere((item) => item.uuid == targetUuid);
print(itemList[itemIndex]);

CodePudding user response：

you can find the index of object as:

void main() {
  final List<Map<String, dynamic>> _people = [
    {"id": "c1", "name": "John Doe", "age": 40},
    {"id": "c2", "name": "Kindacode.com", "age": 3},
    {"id": "c3", "name": "Pipi", "age": 1},
    {"id": "c4", "name": "Jane Doe", "age": 99},
  ];

  // Find index of the person whose id = c3
  final index1 = _people.indexWhere((element) => element["id"] == "c3");
  if (index1 != -1) {
    print("Index $index1: ${_people[index1]}");
  }

  // Find the last index where age > 80
  final index2 = _people.lastIndexWhere((element) => element["age"] > 80);
  if (index2 != -1) {
    print("Index $index2: ${_people[index2]}");
  }
}

Output:

Index 2: {id: c3, name: Pipi, age: 1}
Index 3: {id: c4, name: Jane Doe, age: 99}