Page History

...

This implies that a variable can obscure a type or a package, and a type can obscure a package name. Shadowing, on the other hand, refers to masking variables, fields, types, method parameters, labels, and exception handler parameters in a subscope. Both these differ from hiding wherein an accessible member (typically non-private) that should have been inherited by a subclass is forgone in lieu of a locally declared subclass member that assumes the same name.

In general, do not

...

reuse the name of

• a superclass
• Reuse the name of an interface
• Reuse the name of a field defined in a superclass
• Reuse the name of a field that appears in a different scope within the same method
• Reuse the name of a field, type, or another parameter across packages

...

class Vector {
  private int val = 1;

  public boolean isEmpty() {
    if (val == 1) {   //compares with 1 instead of 0
      return true;
    } else {
      return false;
    }
  }
  //other functionality is same as java.util.Vector
}

// import java.util.Vector; omitted

public class VectorUser {
  public static void main(String[] args) {
    Vector v = new Vector();
    if (v.isEmpty()) {
      System.out.println("Vector is empty");
    }
  }
}

...