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Message:
Answers' appropriateness
Posted by Mekala on May 09, 2000 at 9:38 AM
> While trying to learn Java, I'm making flashcards until I get
> the basics down. I'd be grateful if you could review the Q/A's
> below and send any corrections to: yaeger2@gateway.net
> I'd also appreciate any new Q/A's for my flashcards or
> elaborations on Q/A's below. Thanks, Steve >
> Q1 Explain the appearance of a constructor, when compared to a
> method. > A1 A constructor looks like a method, but it lacks a return
> type. In addition to that Constructor should have the same name as the class name.
>
> Q2 Identify constructors and initializers in class CoffeeCup:
> class CoffeeCup {
> private int innerCoffee;
> //..
> }
> A2 There are none.
You are absolutely correct. JVM will create one default constructor for you. JVM will also initialize the variables which are not inside methods.
>
> Q3 Declare an uninitialized array of Point named myPoints.
> A3 Point myPoints[]; >
> Q4 In the code below, allocate an array of ten references to
> Point, called myPoints, that are initialized to the null
> reference:
> Point myPoints[];
>
> A4 myPoints = new Point[10]; (note: invalid??) >
> Q5 Which string object is for read-only objects ? > A5 The String class is for read-only objects. >
> Q6 Which string object is for modifiable objects ? > A6 The StringBuffer class is for objects that can be modified. >
> Q7 String objects provide ? to obtain the number of characters
> in a string. > A7 String objects provide the length() accessor method to obtain the number of characters in a string. >
> Q8 A class definition has some or all of which six items ? > A8 class variables, instance variables, class methods,
> instance methods, constructors, and static initializers >
> Q9 What is a class ? > A9 A class is a master copy of an object that determines what
> behavior and attributes the object should have. >
> Q10 What's the format of a class called Dog ? > A10 [keywords] class Dog [extends Superclass] [implements Interface] {
> // class body
> } >
> Q11 What's a class variable ? > A11 A class variable is associated with a class of objects,
> not just a single object. >
> Q12 What is AWT ? > A12 AWT stands for Abstract Windowing Toolkit; a set of Java
> classes that has been extended by the Swing windowing classes. They can be used to display and control a GUI. >
> Q13 What is an argument ? > A13 An argument is extra info that is either sent to a program
> at runtime (via the command prompt), or sent to a method during a program. >
> Q14 What is an array ? > A14 An array is a group of variables that share the same name
> and store the same kind of info. >
> Q15 public Virus(String name, int size) {
> author = name;
> maxFileSize = size;
> }
> Write an example of code that could be used to call the above
> constructor. > A15 Virus mumps = new Virus("Hall", 30000);
> or the format....
> Virus [reference] = new Virus("[string]", integer); >
> Q15 public Virus(String name, int size) {
> author = name;
> maxFileSize = size;
> }
> The above constructor could be called only if ? > A15 In the example code, the constructor could be called only
> if a string and an integer were sent as arguments, along
> with the new statement. >
> Q16 In OOP, what's an attribute do ? > A16 An attribute describes an object and distinguishes it from
> others. >
> Q17 Where are attributes kept ? > A17 Attributes are stored in variables. >
>
Your answers are correct
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