(SEM-V) THEORY EXAMINATION 2017-18 PRINCIPLES OF PROGRAMMING LANGUAGES

Principles of Programming Languages (NCS-503)

Section-Wise Important Questions & Study Notes

SECTION–A

(Attempt all questions | 2 × 10 = 20)
This section checks definitions, short explanations, and basic concepts.

Write 2–3 lines only, very crisp answers.

(a) Programming Environment & Language Design

Programming environment (hardware, OS, users, tools) influences syntax, features, efficiency, and security of a language.

(b) Language Semantics

Semantics defines the meaning of program statements, i.e., what a program actually does.

(c) Access Specifiers

Public: accessible everywhere

Private: accessible only within class

Protected: accessible in class and derived classes

(d) Bootstrapping

Bootstrapping is the technique of writing a compiler for a language in the same language itself.

(e) Need of Language Translators

Translators convert high-level language into machine code so that computer can execute programs.

(f) Compiler vs Interpreter

Compiler translates whole program at once; interpreter translates line by line.

(g) Inline Function

Inline function expands function code at call point, reducing function call overhead.

(h) Properties of Constructor

Same name as class, no return type, automatically invoked, used to initialize objects.

(i) LISP Procedure to Find Cube

(defun cube (x) (* x x x))

(j) Abstract Data Type (ADT)

ADT defines data + operations without specifying implementation details.

SECTION–B

(Attempt any THREE | 10 × 3 = 30)
Write structured answers with headings and examples.

2(a) Phases of a Compiler

Explain with block diagram:                         Lexical Analysis

Syntax Analysis                                             Semantic Analysis

Intermediate Code Generation                    Code Optimization

Code Generation                                          Symbol Table & Error Handler

2(b) Facts & Rules in Prolog

Fact: basic statement (e.g., parent(john, ram).)

Rule: logical relation
Example:

grandparent(X,Y) :- parent(X,Z), parent(Z,Y).

2(c) Storage Representation of Data Structures

Explain:                                                    Static allocation

Stack allocation                                       Heap allocation
Mention advantages and use cases.

2(d) Syntactic Criteria of Programming Language

Discuss:                                                    Simplicity

Readability                                               Orthogonality

Expressiveness                                         Uniformity

2(e) Activation Record

Explain fields:                                           Local variables

Parameters                                               Return address

Control link                                              Access link

Explain activation tree and show recursive calls for factorial.

SECTION–C

(Attempt any ONE | 10 × 1 = 10)

3(a) Lambda Calculus

Explain:                                                      Lambda expression

Function abstraction                                 Application

Free variables: not bound by lambda     Bound variables: defined within lambda

OR

3(b) Inheritance                                         Explain concept and types:

Single                                                        Multiple

Multilevel                                                  Hierarchical
Give simple examples in OOP.