Java
What is the time complexity(in "big O notation") of merge sort?
O(N log(N))
What is the time complexity (in "big O notation") of selection sort
O(N^2)
What is the time complexity(in"Big-O notation") of this algorithm
O(n^2)
________________ is a GUI widget toolkit for Java
Swing
In Java, arrays are objects. They are not allocated on the stack, and they do not involve the use of pointer arithmetic, so they avoid the dangers of overflows and out-of-bounds memory accesses that are inherent with C++ arrays
True
In designing classes, it is a good idea to always keep data private. If an instance field needs to be accessed and/or changed from outside the class, this should be done using accessor and mutator methods(also known as getter methods and setter methods)
True
In designing classes, it is a good idea to avoid using too many instance fields in a single class. This is particularly true of multiple, related instance fields of one or more of the basic data types. If you find that you are creating many such fields, the data in those fields might be best be represented by creating a new type(such as the Point data type seen in the previous question)
True
Interfaces are only allowed to have abstract methods and static final attributes
True
Java performs automatic garbage collection; objects that are "unreachable" are periodically collected and removed, and the memory they consumed is reclaimed and made available for new objects
True
Java programs are complied to bytecode, not native machine code
True
One example of the answer to the previous question is Model-View-Controller, which is useful for implementing user interfaces, particularly in GUI-enabled applications
True
When a parameter is passed to a method in Java, pass-by-value is always used. If the parameter being passed is an object reference, the method receives a copy of the original reference
True
You can not store primitive values(int, double, etc.) in an ArrayList
True
___________ delegated the creation of GUI elements(such as text boxes and buttons) to the native operating system platform, while_________ paints these elements onto blank windows, ensuring that they always look and behave the same, regardless of platform
The Abstract Window Toolkit(AWT), Swing
Which of these statements accurately describe the object-oriented features of the Java language?
"Object" is the root class of all objects A subclass can inherit from a superclass Objects can share behaviors with other objects
___________ are a way of structuring your code in order to elegantly express a functional relationship between components. They typically describe a context(a situation which gives rise to a design problem), then they are describe the problem (usually as a set of conflicting forces), and they finally describe a solution as a configuration that balances theses forces
Design patterns
If you do not specify a public or private access modifier when declaring a member( a method or an instance field) of a class, then the member is made private by default
False
In designing classes, it is a good idea to have one class perform a significant percentage of the work in a program, to minimize the number of classes that must be defined
False
Java considers the variable names number and NuMbEr to be identical
False
To create a GUI in Java, we often begin by creating a _______ object, and using this as a container for one or more ________ objects, which we then populate with GUI elements
JFrame;JPanel
The__________________ method produces random numbers
Math_random()
A class can extend only one other class, but can implement many interfaces
True
A class can use all classes from its own package. To use public classes from other packages, you can add the full package name in front of every class name, or you can use an import statement
True
A class must implement all abstract methods inherited from a parent class or from an interface, or else it must be declared abstract itself
True
In Java, all variables must be given a type when they are declared
True
A class contains____________ that are invoked to create objects from the class blueprint
constructors
Repeating a set of instructions a specific number of times is called_____________ repetition
definite(or counter-controlled
In Java, the__________ modifier is used to declare constant variables
final
In java, the_______ modifier is used to declare constant variables
final
The_________ statement is used to execute one action when a condition is true and another action when that condition is false
if........ else
The number used to refer to a particular element of an array is called the element's_____________
index
Inheritance establishes a(n)___________ relationship between the child and the parent class
is-a
A variable known only within the method in which it is declared is called a(n)
local variable
A variable known only within the scope in which it is declared is called a
local variable
A method is invoked with a
method call
A method is invoked with a(n)________
method call
Members of a class specified as_______ are visible only to methods of the class
private
Members of a class specified as__________ are accessible only to methods of the class
private
A member of a class specified as_______ is visible within its own package, and in addition, to a subclass of its class in another package
protected
Members of a class specified as______ are visible to all classes everywhere
public
When it is not known in advance how many times a set of statements will be repeated, a____________ value can be used to terminate the repetition
sentinel(or flag)
The_________ keyword is used to create fields and methods that belong to a class, rather than to an instance of the class. This means that those fields and methods can be accessed without first creating an object.
static
The keyword_________ indicates that a method does not return a value
void
The keyword__________ indicates that a method does not return a value
void