Fixing Java list is abstract cannot be instantiated error

The List type in Java is an Interface type and not a Class type.

If you try to create an instance of List type, Java will throw an error as follows:

List myList = new List();
// ERROR: 'List' is abstract; cannot be instantiated

This is because all Interface types in Java are abstract references used to group related methods and variables together.

When you need to create an instance of List type, you need to instantiate from one of the classes that implement the type.

In Java, there are several classes that implement the List type. They are:

• ArrayList
• LinkedList
• Stack
• Vector
• CopyOnWriteArrayList

Below is an example of how to create a List type instance. Note that you can instantiate the object using any class that implements the List interface:

List myList = new ArrayList();
List secondList = new LinkedList();
List thirdList = new Stack();

The classes that implement a List type are parameterized type classes.

These classes allow you to specify the type argument for the instances created from them.

For example, you can create a List that only stores String values:

List<String> myList = new ArrayList();

myList.add("Nathan");
myList.add("Hello");

Without specifying the type argument using <String> as in the example above, the instance can store values of any type:

List myList = new ArrayList();

myList.add(1);
myList.add("String");
myList.add(true);

In Java, initializing an instance without specifying its type is known as raw types instantiation.

Generally, it’s not recommended to create raw type instances because you lose the type safety feature for these instances.

It’s better to define a List with an explicit type, such as a List<Integer> or List<String>.

And that’s how you instantiate a List type instance in Java. 😉