Question

Discuss the basic differences between the various paradigms of the programming languages. In what circumstances is each one particularly strong, and in what circumstances is each one particularly feeble? Elaborate with examples and sample coding from your project and from other sources.

The languages preferred to discuss are C++, C#, Prolog and JavaScript

Answer 1

1)Imperative programming: good for simple programs
it is step by step programming.in this paradigm, statements are defined in a sequence in which operations are performed to achieve the desired output.it is oldest programming style.
example : addition of two integers in c++
#include<iostream>
using namespace std;
int main()
{
   int a,b,c;
   a=10,b=10;
   c=a+b;
   cout<<"Sum is "<<c;
   return 0;
}

2)Declarative programming: good for data base programming.
specifies that what is the output without mentioning the logic behind the output.
example:
select empname from employee where empsal>10000

3)Structured programming:good when there is a need to control the flow of program.
it is something like imperative programming but focuses on modular approach by the extensive use of looping blocks,subroutines,blocks,nested block to hold more control over the program.

example : handling 2D array in C++
#include<iostream>
using namespace std;
int main()
{
   int arr[2][2]={{1,2},{3,4}};
   int i,j;
   for (i=0;i<2;i++)
   {
       for(j=0;j<2;j++)
       {
      
       cout<<arr[i][j];
   }
   cout<<endl;
      
   }
  
  
   return 0;
}

4)Procedural programming:
it is the combination of structured and imperative programming.
this type of programming paradigm is based on the extensive use of procedural calls.

Example
#include<iostream>
using namespace std;
void proc1();

int main()
{
   proc1();//procedural call
  
  
  
   return 0;
}
void proc1()
{
   cout<<"this is procedural call"<<endl;
}

5)Object oriented programming:good for solving real world problems.

Object oriented pricnples are based on real life scenarios
1. Encapsulation: In object oriented paradigm, data is not allowed to move freely around the program.
data and function are encapsulated together to form a single unit cales class.

Abstraction: means to disclose only necessary detail about the object(a real world entity).

2. Inheritance: offers code reusability, a new class(child class) can be derived from an existing class(old class).

3. polymorphism:- having more than one forms.
detail is given below

Object,
class,
abstraction/encapsulation,
Polymorphism,
inheritance/genralization/specialization,
Aggregation/Composition,
Association
Object:- Any real world entity which can be represented in real world.
object can be described by its attributes.
for example :- A student is an object, because one can describe a student by the following attributes
a)Name of student
b)Date of birth
c)Course
d)contact_number
e)Roll_number
and so on.
There are three important aspects about any object
1)State
2) behavior
3)Identity
state:-a student may be in state of listening lecture,
behavior:- the behavior of student is to solve assignments
Identity:-every object should be identified uniquely.
every student is uniquely identified by his/her roll number.
class:- is a template/blueprint which is used to create object.
with the help of class one can define that what type of object will be created.
inheritance:- A new class(derived class) can be derived from the existing class(super class).
it offers code reusability
abstraction:- to disclose only necessary details about the object.
encapsulation:- function and data are wrapped together to form a single unit(class).
ultimately, unnecessary details about the object will be hidden.
polymorphism:- having more than one forms.
example:- touch screen of a mobile phone can be used to perform various tasks.
same touch screen can be used to send messages,dial phone numbers,play audio/video, and so on.
In few programming languages + operator can be used to perform mathematical addition as well as string concatenation, so + operator exhibits polymorphism.

Example: represent a student as an object in C#

using System;

namespace ConsoleApplication25
{
class Program
{
static void Main(string[] args)
{// create object
student student1 = new student();
student1.setname("John");
Console.WriteLine( student1.getname());
Console.ReadKey();

  
}
}
class student
{
public string name;
  
public void setname(string name)
{
this. name=name ;

}
public string getname()
{
return this.name ;
}
  
}
}

6) Functional programming: is useful when same type of task is repeated number of times.
this style of programming uses functions.
function returns a value.

Example in C++
function to return the addition of two numbers

#include<iostream>
using namespace std;

int add1(int,int);
int main()
{
  
   cout<<add1(5,5);//function calling
  
  
   return 0;
}

int add1(int a,int b)
{
   return a+b;
}