Conteúdo do Curso
Introduction to Dart
Introduction to Dart
Indexes
About Indexes
Every element in the List, or String, has a unique address. Such addresses are called indexes:
Indexes start from 0. The first element is assigned the index 0, the second element is assigned the index 1, and so on.
We can retrieve an element from the list using its index with the following syntax:
Example
Let's print the element at index 1 from the List:
main
void main() { List<String> names = ["Bob", "John"]; print(names[1]); // John }
Editing
Dart allows modifying the value of an item in a List. In other words, one can re-write the value of a List item.
main
void main() { List cars = ["BMW", "Porsche", "Ford"]; cars[0] = "Toyota"; print (cars); // ["Toyota", "Porsche", "Ford"] }
The above example updates the value of the List item with index 0. The output of the code will be − [‘Toyota’, ‘Porsche’, ‘Ford’]
String Indexes
In a String, we also have indexes.
main
void main() { String user = "Alex"; print(user[0]); }
Note
The only difference between Indexes in a
Stringand Indexes in aListis that in Lists, we can update values at those addresses, whereas in Strings, we cannot.
Task
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