List in Dart#

About#

• Lists in Dart are ordered collections of items.
• They can store elements of the same type or mixed types.
• Lists are zero-indexed, meaning the first element is at index 0.
• Dart provides various list operations and methods for manipulation.

Main Topics#

1. List Creation

   • Definition: How to create and initialize lists in Dart.
   • Example:

     void main() {
       // Creating an empty list
       List<String> fruits = [];
     
       // Creating a list with initial values
       List<String> vegetables = ['Carrot', 'Potato', 'Spinach'];
     }
     

2. List Operations

   • Definition: Methods for adding, removing, and accessing elements in a list.
   • Example:

     void main() {
       List<String> fruits = ['Apple', 'Banana'];
     
       // Adding an element
       fruits.add('Orange');
     
       // Removing an element
       fruits.remove('Banana');
     
       // Accessing elements
       print(fruits[0]); // Outputs: Apple
     }
     

3. List Types

   • Definition: Fixed-length vs. growable lists.
   • Example:

     void main() {
       // Fixed-length list
       List<int> fixedList = List.filled(3, 0);
       fixedList[0] = 1;
     
       // Growable list
       List<int> growableList = [];
       growableList.add(1);
       growableList.add(2);
     
       print(fixedList); // Outputs: [1, 0, 0]
       print(growableList); // Outputs: [1, 2]
     }
     

4. List Iteration

   • Definition: Techniques for looping through list elements.
   • Example:

     void main() {
       List<String> fruits = ['Apple', 'Banana', 'Orange'];
     
       // Using a for loop
       for (int i = 0; i < fruits.length; i++) {
         print(fruits[i]);
       }
     
       // Using forEach
       fruits.forEach((fruit) {
         print(fruit);
       });
     }
     

5. List Methods

   • Definition: Common methods for manipulating lists such as add(), remove(), insert(), and sort().
   • Example:

     void main() {
       List<String> fruits = ['Apple', 'Banana', 'Orange'];
     
       // Adding an element
       fruits.add('Grapes');
     
       // Removing an element
       fruits.remove('Banana');
     
       // Inserting an element at a specific index
       fruits.insert(1, 'Blueberry');
     
       // Sorting the list
       fruits.sort();
     
       print(fruits); // Outputs: [Apple, Blueberry, Grapes, Orange]
     }
     

How to Use#

• Creating a List: Use square brackets [] or the List constructor.
• Accessing Elements: Use index notation (e.g., list[index]) to get or set elements.
• Modifying Lists: Add, remove, or change elements using list methods.
• Iterating: Use loops or methods like forEach to process list elements.

How It Works#

• Creation: Lists can be created with initial values or as empty.
• Operations: Modify lists by accessing elements with indices and using methods for adding, removing, or updating.
• Iteration: Loop through lists using for, forEach, or other iteration methods.
• Types: Fixed-length lists have a set size, while growable lists can expand dynamically.

Example of List Operations:

void main() {
  // Creating a growable list
  List<String> fruits = ['Apple', 'Banana'];

  // Adding elements
  fruits.add('Orange');

  // Removing an element
  fruits.remove('Banana');

  // Accessing elements
  print(fruits[0]); // Outputs: Apple

  // Iterating through the list
  fruits.forEach((fruit) {
    print(fruit); // Outputs: Apple, Orange
  });
}