Explanation:
In Java, an interface is a collection of abstract methods. It cannot be instantiated directly because it is not a concrete class. However, other classes can implement an interface and provide the implementation for its methods.
The error “no primary or single unique constructor found for interface java.util.list” occurs when trying to create an instance of an interface, such as the List interface in the java.util package.
Interfaces do not have constructors like classes do, so you cannot create an instance of an interface directly. Instead, you need to create an instance of a class that implements the interface.
Example:
// Creating an instance of List interface gives an error
List<String> myList = new List<>(); // Error: no primary or single unique constructor found for interface java.util.list
// Instead, create an instance of a class that implements List interface
List<String> myList = new ArrayList<>();In the example above, the initial attempt to create an instance of the List interface (using new List<>()) causes an error. To fix it, we create an instance of the ArrayList class (which implements the List interface) using new ArrayList<>().