Initializing and using Interfaces in Java? -

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first of all, learned that:

  • you cannot instantiate interface
  • an interface doesn't implement functions

after seeing following java code:

public class myclasstest {      public static void main(string[] args) {          // string charsequence?          charsequence c = "java";          system.out.println(c);         system.out.println(c.length());     } }

i confused when learned charsequence interface

  • how can use interface object , initialize it?

  • why charsequence implements length function if interface?

"java" instance of string class, implements charsequence interface, includes implementing length() method. therefore can assign charsequence variable.

a variable type interface can assigned references instances (objects) of classes implement interface.


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