Tag: programming languages

class Line { Line 1. public class Point { public int x,y; } Line 2. public Point getPoint() { return new Point(); } Line 3. } Line 4. class Triangle { Line 5. public Triangle() { Line 6. // insert code here Line 7. } 18. } Which code, inserted at line Line 6, correctly retrieves a local instance of a Point object? A. Point p = Line.getPoint(); B. Line.Point p = Line.getPoint(); C. Point p = (new Line()).getPoint(); D. Line.Point p = (new Line()).getPoint();

Given a method that must ensue that its parameter is not null: Line 1. public void someMethod(Object value) { Line 2. // check for null value Line 3. System.out.println(value.getClass()); Line 4. } What, inserted at line 2, is the appropriate way to handle a null value? A. assert value == null; B. assert value !null, “value is null”; C. if (value == null) { throw new AssertionException(”value is null”); D. if (value == null) { throw new IllegalArgumentException(”value is null”);

Line 1. public class ClassA { Line 2. public void count(int i) { Line 3. count(++i); Line 4. } Line 5. } And: Line 6. ClassA a = new ClassA(); Line 7. a.count(3); Which exception or error should be thrown by the virtual machine? A. StackOverflowError B. NullPointerException C. NumberFormatException D. IllegalArgumentException E. ExceptionlnlnitializerError

public class Foo implements java.io.Serializable { Line1. private int x; Line2. public int getX() { return x; } Line 3.publicFoo(int x){this.x=x; } Line 4. private void writeObject( ObjectOutputStream s) Line 5. throws IOException { Line 6. // insert code here Line 7. } Line 8. } Which code fragment, inserted at line Line 6, will allow Foo objects to be correctly serialized and deserialized? A. s.writeInt(x); B. s.serialize(x); C. s.writeObject(x); D. s.defaultWriteObject();