Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scoping

Students can Download Computer Science Chapter 3 Scoping Questions and Answers, Notes Pdf, Samacheer Kalvi 12th Computer Science Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scoping

Samacheer Kalvi 12th Computer Science Scoping Text Book Back Questions and Answers

PART – 1
I. Choose The Best Answer

Question 1.
Which of the following refers to the visibility of variables in one part of a program to another part of the same program?
(a) Scope
(b) Memory
(c) Address
(d) Accessibility
Answer:
(a) Scope

Question 2.
The process of binding a variable name with an object is called ………………………….
(a) Scope
(b) Mapping
(c) Late binding
(d) Early binding
Answer:
(b) Mapping

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 3.
Which of the following is used in programming languages to map the variable and object?
(a) ::
(b) : =
(c) =
(d) = =
Answer:
(c) =

Question 4.
Containers for mapping names of variables to objects is called ………………………….
(a) Scope
(b) Mapping
(c) Binding
(d) Namespaces
Answer:
(d) Namespaces

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 5.
Which scope refers to variables defined in current function?
(a) Local Scope
(b) Global scope
(c) Module scope
(d) Function Scope
Answer:
(a) Local Scope

Question 6.
The process of subdividing a computer program into separate sub – programs is called ………………………….
(a) Procedural Programming
(b) Modular programming
(c) Event Driven Programming
(d) Object oriented Programming
Answer:
(b) Modular programming

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 7.
Which of the following security technique that regulates who canuse resources in a computing environment?
(a) Password
(b) Authentication
(c) Access control
(d) Certification
Answer:
(c) Access control

Question 8.
Which of the following members of a class can be handled only from within the class?
(a) Public members
(b) Protected members
(c) Secured members
(d) Private members
Answer:
(d) Private members

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 9.
Which members are accessible from outside the class?
(a) Public members
(b) Protected members
(c) Secured members
(d) Private members
Answer:
(a) Public members

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 10.
The members that are accessible from within the class and are also available to its subclasses is called ………………………….
(a) Public members
(b) Protected members
(c) Secured members
(d) Private members
Answer:
(b) Protected members

PART – II
II. Answer The Following Questions

Question 1.
What is a scope?
Answer:
Scope refers to the visibility of variables, parameters and functions in one part of a program to another part of the same program.

Question 2.
Why scope should be used for variable. State the reason?
Answer:
Essentially, variables are addresses (references, or pointers), to an object in memory. When you assign a variable with := to an instance (object), you’re binding (or mapping) the variable to that instance. Multiple variables can be mapped to the same instance.

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 3.
What is Mapping?
Answer:
The process of binding a variable name with an object is called mapping. = (equal to sign) is used in programming languages to map the variable and object.

Question 4.
What do you mean by Namespaces?
Answer:
Programming languages keeps track of all these mappings with namespaces. Namespaces are containers for mapping names of variables to objects.

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 5.
How Python represents the private and protected Access specifiers?
Answer:
Private members of a class are denied access from the outside of the class. They can be handled only within the class.
Protected members of a class are accessible from within the class and are also available to its sub-classes. No other process is permitted access to it.

PART – III
III. Answer The Following Questions

Question 1.
Define Local scope with an example?
Answer:
Local Scope:
Local scope refers to variables defined in current function. Always, a function will first look up for a variable name in its local scope. Only if it does not find it there, the outer scopes are checked.
Look at this example
Samacheer kalvi 12th Computer Science Solutions Chapter 3 Scoping
On execution of the above code the variable a displays the value 7, because it is defined and available in the local scope.

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 2.
Define Global scope with an example?
Answer:
Global Scope:
A variable which is declared outside of all the functions in a program is known as global variable. This means, global variable can be accessed inside or outside of all the functions in a program. Consider the following example
Samacheer kalvi 12th Computer Science Solutions Chapter 3 Scoping
On execution of the above code the variable a which is defined inside the function displays the value 7 for the function call Disp( ) and then it displays 10, because a is defined in global scope.

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 3.
Define Enclosed scope with an example?
Answer:
Enclosed Scope:
All programming languages permit functions to be nested. A function (method) with in another function is called nested function. A variable which is declared inside a function which contains another function definition with in it, the inner function can also access the variable of the outer function. This scope is called enclosed scope. When a compiler or interpreter search for a variable in a program, it fist search Local, and then search Enclosing scopes. Consider the following example
Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scoping

Question 4.
Why access control is required?
Answer:
Access control is a security technique that regulates who or what can view or use resources in a computing environment.
It is a fundamental concept in security that minimizes risk to the object. In other words access control is a selective restriction of access to data.
In Object oriented programming languages it is implemented through access modifies.
Classical object – oriented languages, such as C++ and Java, control the access to class members by public, private and protected keywords.

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 5.
Identify the scope of the variables in the following pseudo code and write its output?
Answer:
Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scoping
Output:
Red, blue, green
Red blue
Red

PART – IV
IV. Answer The Following Questions

Question 1.
Explain the types of scopes for variable or LEGB rule with example?
Answer:
LEGB rule
Scope also defines the order in which variables have to be mapped to the object in order to obtain the value. Let us take a simple example as shown below:

  1. x: = ‘outer x variable’
  2. display ( ):
  3. x: = ‘inner x variable’
  4. print x
  5. display ( )

When the above statements are executed the statement (4) and (5) display the result as
Output
outer x variable
inner x variable
Above statements give different outputs because the same variable name x resides in different scopes, one inside the function display( ) and the other in the upper level. The value ‘outer x variable’ is printed when x is referenced outside the function definition. Whereas when display( ) gets executed, ‘inner x variable’ is printed which is the x value inside the function definition. From the above example, we can guess that there is a rule followed, in order to decide from which scope a variable has to be picked. The LEGB rule is used to decide the order in which the scopes are to be searched for scope resolution. The scopes are listed below in terms of hierarchy (highest to lowest).
Samacheer kalvi 12th Computer Science Solutions Chapter 3 Scoping
Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scoping

Types of Variable Scope:
There are 4 types of Variable Scope, let’s discuss them one by one:

Local Scope:
Local scope refers to variables defined in current function. Always, a function will first look up for a variable name in its local scope. Only if it does not find it there, the outer scopes are checked. Look at this example
Samacheer kalvi 12th Computer Science Solutions Chapter 3 Scoping
On execution of the above code the variable a displays the value 7, because it is defined and available in the local scope.

Global Scope:
A variable which is declared outside of all the functions in a program is known as global variable. This means, global variable can be accessed inside or outside of all the functions in a program. Consider the following example
Samacheer kalvi 12th Computer Science Solutions Chapter 3 Scoping
On execution of the above code the variable a which is defined inside the function displays the value 7 for the function call Disp( ) and then it displays 10, because a is defined in global scope.

Enclosed Scope:
All programming languages permit functions to be nested. A function (method) with in another function is called nested function. A variable which is declared inside a function which contains another function definition with in it, the inner function can also access the variable of the outer function. This scope is called enclosed scope. When a compiler or interpreter search for a variable in a program, it first search Local, and then search Enclosing scopes. Consider the following example
Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scoping
In the above example Disp1 ( ) is defined with in Disp ( ). The variable ‘a’ defined in Disp ( ) can be even used by Disp 1 ( ) because it is also a member of Disp

Built – in Scope:
Finally, we discuss about the widest scope. The built-in scope has all the names that are pre-loaded into the program scope when we start the compiler or interpreter. Any variable or module which is defined in the library functions of a programming language has Built-in or module scope. They are loaded as soon as the library files are imported to the program.
Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scoping
Normally only Functions or modules come along with the software, as packages. Therefore they will come under Built in scope.

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 2.
Write any Five Characteristics of Modules?
Answer:
Characteristics of Modules:
The following are the desirable characteristics of a module.

  1. Modules contain instructions, processing logic, and data.
  2. Modules can be separately compiled and stored in a library.
  3. Modules can be included in a program.
  4. Module segments can be used by invoking a name and some parameters.
  5. Module segments can be used by other modules.

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 3.
Write any five benefits in using modular programming?
Answer:
The benefits of using modular programming include:

  1. Less code to be written.
  2. A single procedure can be developed for reuse, eliminating the need to retype the code many times.
  3. Programs can be designed more easily because a small team deals with only a small part of the entire code.
  4. Modular programming allows many programmers to collaborate on the same application.
  5. The code is stored across multiple files.
  6. Code is short, simple and easy to understand.
  7. Errors can easily be identified, as they are localized to a subroutine or function.
  8. The same code can be used in many applications.
  9. The scoping of variables can easily be controlled.

Practice Programs

Question 1.
Observe the following diagram and Write the pseudo code for the following?
Answer:
Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scoping
sum ( ):
num 1: = 20
sum 1 ( )
num1: = num1 + 10 sum2 ( )
num1: = num1 + 10
sum2 ( ) sum1 ( ) num1: = 10
sum ( )
Print num 1

Samacheer kalvi 12th Computer Science Scoping Additional Questions and Answers

PART -1
I. Choose The Best Answer

Question 1.
Names paces are compared with ……………………….
(a) Programs
(b) Dictionaries
(c) Books
(d) Notebooks
Answer:
(b) Dictionaries

Question 2.
Write the output (value stored in b)
1. a: = 5
2. b: = a
(a) 0
(b) 3
(c) 5
(d) 2
Answer:
(c) 5

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 3.
Find the value of a.
1. a: = 5
2. b: = a
3. a: = 3
(a) 0
(b) 3
(c) 5
(d) 2
Answer:
(b) 3

Question 4.
The ………………………. of a variable is that part of the code where it is visible.
Answer:
Scope

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 5.
The duration for which a variable is alive is called its ……………………………
(a) Scale
(b) Life time
(c) Static
(d) Function
Answer:
(b) Life time

Question 6.
…………………………… also defines the order in which variables have to be mapped to the object in order to obtain the value.
(a) Scope
(b) Local
(c) Event
(d) Object
Answer:
(a) Scope

Question 7.
The …………………………… rule is used to decide the order in which the scopes are to be searched for scope resolution.
Answer:
LEGB

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 8.
How many types of variable scopes are there?
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(d) 4

Question 9.
A function will first look up for a variable name in its …………………………… scope.
(a) Local
(b) Enclosed
(c) Global
(d) Built in
Answer:
(a) Local

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 10.
A variable which is declared outside of all the functions in a program is known as …………………………… variable.
(a) L
(b) E
(c) G
(d) B
Answer:
(c) G

Question 11.
A …………………………… variable can be accessed inside or outside of all the functions in a program.
(a) Local
(b) Global
(c) Enclosed
(d) Built – in
Answer:
(b) Global

Question 12.
A function defined within another function is called …………………………… function
(a) Member
(b) Looping
(c) Nested
(d) Invariant
Answer:
(c) Nested

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 13.
Functions are otherwise called as …………………………..
(a) Methods
(b) Attributes
(c) Class
(d) Structures
Answer:
(a) Methods

Question 14.
The scope of nested function is …………………………… scope
(a) Local
(b) Global
(c) Enclosed
(d) Built – in
Answer:
(c) Enclosed

Question 15.
When a compiler or interpreter search for a variable in a program, it first search and then search …………………………… scope
(a) L, E
(b) EG
(c) GB
(d) BL
Answer:
(a) L, E

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 16.
Built – in scopes are called as …………………………… scope.
Answer:
Module

Question 17.
Any variable or module defined in the library functions has …………………………… scope.
Answer:
Built – in

Question 18.
Variables of built – in scopes are loaded as …………………………… files.
(a) Exe
(b) Linker
(c) Object
(d) Library
Answer:
(d) Library

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 19.
Identify which is not a variable scope.
(a) Module
(b) Built – in
(c) Enclosed
(d) Pointer
Answer:
(d) Pointer

Question 20.
A single …………………………… can contain one or several statements closely related to each other.
Answer:
Module

Question 21.
A …………………………… is a part of a program.
(a) Code
(b) Module
(c) Flowchart
(d) System software
Answer:
(b) Module

Question 22.
Identify which is not a module?
(a) Algorithm
(b) Procedures
(c) Subroutines
(d) Functions
Answer:
(a) Algorithm

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 23.
Find the wrong statement from the following
(a) Modules contains data and instructions
(b) Modules can be included in a program
(c) Modules cannot have processing logic
(d) Modules can be separately combined
Answer:
(c) Modules cannot have processing logic

Question 24.
Which is true about modular programming?
(a) Single procedure can be reused
(b) Single procedure cannot be reused
Answer:
(a) Single procedure can be reused

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 25.
The arrangement of private instance variables and public methods ensures the principle of ……………………………
(a) Security
(b) Data encapsulation
(c) Inheritance
(d) Class
Answer:
(b) Data encapsulation

Question 26.
All members in a python class are by …………………………… default.
(a) Private
(b) Public
(c) Protected
(d) Local
Answer:
(b) Public

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 27.
The members in C ++ and Java, by default are ……………………………
(a) Private
(b) Public
(c) Protected
(d) Local
Answer:
(a) Private

PART – II
II. Answer The Following Questions

Question 1.
Define life time?
Answer:
The duration for which a variable is alive is called its ‘life time’.

PART – III
III. Answer The Following Questions

Question 1.
Write the output for the pseudo code?
Answer:

  1. x: = ‘outer x variable’
  2. display( ):
  3. x: = ‘inner x variable’
  4. print x
  5. display Q

Output:
outer x variable
inner x variable

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 2.
List the scope in hierarchical order from highest to lowest?
Answer:
Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scoping
Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scoping

Question 3.
Write note on modules?
Answer:
A module is a part of a program. Programs are composed of one or more independently developed modules. A single module can contain one or several statements closely related each other. Modules work perfectly on individual level and can be integrated with other modules.

Samacheer Kalvi 12th Computer Science Solutions Chapter 3 Scopingn

Question 4.
Write note on public members?
Answer:
Public members (generally methods declared in a class) are accessible from outside the class. The object of the same class is required to invoke a public method. This arrangement of private instance variables and public methods ensures the principle of data encapsulation.

Leave a Comment

Your email address will not be published. Required fields are marked *