Question

I’m somewhat confused about the code below:

class BooksTestDrive {
  public static void main(String [] args) {
      String [] islands = new String[4];

      islands[0] = "Bermuda";
      islands[1] = "Fiji";
      islands[2] = "Azores";
      islands[3] = "Cozumel";


  }
}

I was under the assumption that this would return a NullPointerException error because no object is initialized.

I assumed I would need to do

class BooksTestDrive {
  public static void main(String [] args) {
      String [] islands = new String[4];
      islands[0] = new String();

//    etc..

      islands[0] = "Bermuda";
      islands[1] = "Fiji";
      islands[2] = "Azores";
      islands[3] = "Cozumel";


  }
}

Why is it okay here?
Why is the exception not thrown?

Answer 1

“Bermuda” is a String literal and String str = "Bermuda"; implies that str is a new String object with the value “Bermuda”.

String str = "Bermuda";
String str = new String("Bermuda");

The lines above do the same work, but with one difference, first string instance is managed by Java String constant pool and the second one is not.