Flutter & Dart: Conditional remove elements from List

To remove elements from a list based on one or many conditions, you can use the built-in removeWhere() method.

Example

Let’s say we have a product list, and the task is to remove all products whose prices are higher than 100:

import 'package:flutter/foundation.dart';

// Define how a product looks like
class Product {
  final double id;
  final String name;
  final double price;
  Product(this.id, this.name, this.price);
}

void main() {
  // Generate the product list
  List<Product> products = [
    Product(1, "Product A", 50),
    Product(2, "Product B", 101),
    Product(3, "Product C", 200),
    Product(4, "Product D", 90),
    Product(5, "Product E", 400),
    Product(6, "Product F", 777)
  ];

  // remove products whose prices are greater than 100
  products.removeWhere((product) => product.price > 100);

  // Print the result
  debugPrint("Product(s) whose prices are less than or equal to 100:");
  for (var product in products) {
    debugPrint(product.name);
  }
}

Output:

Product(s) whose prices are less than 100:
Product A
Product D

Further reading:

• Dart: Convert Class Instances (Objects) to Maps and Vice Versa
• 2 Ways to Get a Random Item from a List in Dart (and Flutter)
• Dart: Converting a List to a Map and Vice Versa
• Flutter: Convert UTC Time to Local Time and Vice Versa
• Dart: Convert Timestamp to DateTime and vice versa
• Flutter: Creating OTP/PIN Input Fields (2 approaches)

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