Generics

Dart originally came with generics—a facility of generic programming. We have to tell the static analyzer the permitted type of a collection so it can inform us at compile time if we insert a wrong type of object. As a result, programs become clearer and safer to use. We will discuss how to effectively use generics and minimize the complications associated with them.

Raw types

Dart supports arrays in the form of the List class. Let's say you use a list to store data. The data that you put in the list depends on the context of your code. The list may contain different types of data at the same time, as shown in the following code:

// List of data
List raw = [1, "Letter", {'test':'wrong'}];
// Ordinary item
double item = 1.23;

void main() {
  // Add the item to array
  raw.add(item);
  print(raw);
}

In the preceding code, we assigned data of different types to the raw list. When the code executes, we get the following result:

[1, Letter, {test...