Object Oriented Concept MCQ

Test your knowledge with important Object Oriented Concept MCQ and their applications. These MCQs are beneficial for competitive exams too. Explore 30 + more Object Oriented Concept MCQs at Bissoy

• PHP have not yet supported constructor overloading. 
  ক

  TRUE

  খ

  FALSE
• You can overwrite a Singleton with the wrong kind of data. 
  ক

  TRUE

  খ

  FALSE
• Even if you don’t delete the object yourself using . . . . . , PHP still calls the destructor when it determines that the object is no longer used.
  ক

  destructor

  খ

  del()

  গ

  rem()

  ঘ

  unset()
•  . . . . . . is a class which can only be instantiated once. You can effectively only have one object per . . . . . class in an application.
  ক

  Constructor, Singleton

  খ

  Singleton, Constructor

  গ

  Singleton, Singleton

  ঘ

  Loader, Loader
• You can invoke class constructors that don’t have any relation to the instantiated object by simply prefacing _constructor with the class name like.
  ক

  classname::__construct()

  খ

  classname:__construct()

  গ

  classname=>__construct()

  ঘ

  classname->__construct()
• Constructor and destructor methods have no . . . . . . and are called automatically - they cannot be called explicitly and consequently their declarations need no access specifier. 
  ক

  parameters

  খ

  destructor

  গ

  return value

  ঘ

  aproval
• In . . . . . constructors, it is important to remember that you have to call the parent constructor explicitly.
  ক

  Singleton

  খ

  secure

  গ

  public

  ঘ

  subclass
• PHP recognises constructors by the name . . . . .
  ক

  _construct

  খ

  __construct

  গ

  __constructor

  ঘ

  _constructor
• Which of the below is most useful for debugging:
  ক

  print()

  খ

  printf()

  গ

  print_r()

  ঘ

  echo
• Heredoc's are a great alternative to quoted strings because of increased readability and maintainability.
  ক

  True

  খ

  False
• The functions strtolower() and strtoupper() work on individual characters and not on entire strings.
  ক

  True

  খ

  False
• PHP strings are binary-safe (i.e. they can contain null bytes) . Their size is limited only by the amount of memory that is available to PHP.
  ক

  True

  খ

  False
• In PHP, the difference between double quote and single quote is that variables . . . . in single quoted strings whereas they . . . . . in double quoted strings.
  ক

  are not parsed, are parsed

  খ

  are parsed, are not parsed

  গ

  are class, are not class

  ঘ

  are variables, are not variables
• Child classes are defined using the keyword .....
  ক

  extends

  খ

  extents

  গ

  child_class

  ঘ

  extend_class
• A class may contain its own .............
  ক

  variables

  খ

  functions

  গ

  constants

  ঘ

  both A and B

  ঙ

  all of above
• The pseudo-variable ...... is available inside any class method when that method is called from within an object context.
  ক

  $construct

  খ

  #this

  গ

  $those

  ঘ

  $this
• When you extend a class, the subclass inherits all of the ........ methods from the parent class.
  ক

  Public

  খ

  private

  গ

  protected

  ঘ

  both A and C
• You access an object’s properties and methods using the ....... operator ( a hyphen followed by a greater than symbol).
  ক

  >>

  খ

  =>

  গ

  ->

  ঘ

  none of above
• All PHP classes come with a default constructor that takes .... arguments.
  ক

  one

  খ

  two

  গ

  three

  ঘ

  no
• The visibility of a property or method can be defined by prefixing the declaration with the keywords public, protected or private. Class members declared public can be accessed everywhere. Members declared protected can be accessed only within the class itself and by inherited classes. Members declared as private are not accessible.
  ক

  True

  খ

  False
• Once a class has been defined, objects can be created from the class with the ....... keyword.
  ক

  new object

  খ

  construct

  গ

  new

  ঘ

  both A and C
• PHP makes it possible to automatically execute code when a new instance of a class is created, using a special class method called a ........ 
  ক

  destructor

  খ

  constructor

  গ

  friend

  ঘ

  initial
• A valid class name starts with a ......., followed by any number of letters, numbers, or underscores.<br>1. Number<br>2. Letter<br>3. Period<br>4. Underscore<br>
  ক

  Option 1 and 4

  খ

  Option 2 and 3

  গ

  Option 3 and 4

  ঘ

  Option 1 and 3
• The extent to which proximate procedures are related to one another is known as.
  ক

  Coupling

  খ

  Balancing

  গ

  Cohesion

  ঘ

  Co-relation
• Placing a static method for generating _______ objects in the ________ class is convenient.
  ক

  child parent

  খ

  parent child

  গ

  final static

  ঘ

  static final
• Object-oriented code tries to minimize dependencies by moving responsibility for handling tasks away from _______ and toward the objects in the system.
  ক

  server code

  খ

  client code

  গ

  machine code

  ঘ

  procedural code
• How many times can you define _______ autoload in a process?
  ক

  once

  খ

  twice

  গ

  thrice

  ঘ

  as many times as needed
• Which keyword can be used to fix the above error?
  ক

  fix

  খ

  join

  গ

  use

  ঘ

  namespace
• Which of the following can you place inside a namespace?<br>1. classes<br>2. functions<br>3. variables
  ক

  1

  খ

  2

  গ

  3

  ঘ

  All of the mentioned
• Which of the following is/are true for an abstract class?<br>1. A class is declared abstract by prefacing the definition with the word abstract.<br>2. A class is declare abstract by using the keyword implements.<br>3. It is a class that really isn’t supposed to ever be instantiated but instead serves as a base class.<br>4. Attempting to instantiate an abstract class results in an error.
  ক

  Only 2

  খ

  All of the mentioned

  গ

  2 and 4

  ঘ

  2, 3 and 4