plintron interview questions and answers - Wikitechy

What is Data Structure ?

Editor — Tue, 13 Jul 2021 10:41:28 +0000

What is Data Structure ?

Data structures are used to store data in a computer in an organized form. In C language Different types of data structures are; Array, Stack, Queue, Linked List, Tree.

Array

An Array is a collection of similar data type value in a single variable.
An array is a derived data type in C, which is constructed from fundamental data type of C language.

Stack

Stack is linear data structure.
In stack addition of new data item and deletion of already existing data item is done from only one end, known as top.
Working of stack on the basis of Last-in-First-out (LIFO) principal, it means last entered item remove first.

Queue

Queue is work on the principal of First-In-First-Out (FIFO), it means first entered item remove first.
Queue have two end front and back, from front you can insert element and from back you can delete element.

Linked List

Linked list is a special type of data structure where all data elements are linked to one another.
Linked list is the collection of nodes and every nodes contains two parts data part and address part.

Tree

Stores data in a non linear form with one root node and sub nodes.

What are the OOPS concepts ?

Editor — Mon, 12 Jul 2021 21:44:25 +0000

What are the OOPS concepts ?

The OOPs Concepts are,

Objects
Classes
Abstraction
Encaptulation
Inheritance
Polymorphism
Dynamic binding
Messege passing

Objects

An object is an abstraction of a real-world entity. It may represent a person, a place, a number and icons or something else that can be modelled. Any data in an object occupy some space in memory and can communicate with each other.

Classes:

A class is a collection of objects having common features. It is a user defined datatype which has data members as well functions that manipulate these data’s.

Abstraction:

It can be defined as the separation of unnecessary details or explanation from system requirements so as to reduce the complexities of understanding requirements.

Encapsulation:

It is a mechanism that puts the data and function together. It is the result of hiding implementation details of an object from its user.The object hides its data to de accessed by only those functions which are packed in the class of that object.

Inheritance:

It is the relationship between two classes of object such that one of the classes ,the child takes all the relevant features of other class the parent. Inheritance bring about reusability.

Polymorphism:

Polymorphism means having many forms that in a single entity can takes more than one form. Polymorphism is implemented through operator overloading and function overloading.

Dynamic Binding:

Dynamic binding is the process of resolving the function to be associated with the respective functions calls during their runtime rather than compile time.

Message Passing:

Every data in an object in oops that is capable of processing request known as message .
All object can communicate with each other by sending message to each other

Explain Call by Reference in C language ?

Editor — Mon, 12 Jul 2021 20:50:02 +0000

Explain Call by Reference in C language ?

Call by value

In call by reference, original value is modified because we pass reference (address).
Here, address of the value is passed in the function, so actual and formal arguments shares the same address space. Hence, value changed inside the function, is reflected inside as well as outside the function.

Sample Code

#include
void change(int *num) 
{    
    printf("Before adding value inside function num=%d \n",*num);    
    (*num) += 100;    
    printf("After adding value inside function num=%d \n", *num);    
}      
int main() 
{    
    int x=100;    
    printf("Before function call x=%d \n", x);    
    change(&x);    
    printf("After function call x=%d \n", x);    
    return 0;  
}

Output

Before function call x=100
Before adding value inside function num=100
After adding value inside function num=200
After function call x=200

Explain Call by Value in C language ?

Editor — Mon, 12 Jul 2021 20:43:35 +0000

Explain Call by Value in C language ?

Call by value

In call by value, original value is not modified.
In call by value, value being passed to the function is locally stored by the function parameter in stack memory location. If you change the value of function parameter, it is changed for the current function only.
It will not change the value of variable inside the caller method such as main().

Sample Code

#include
void change(int num) 
{    
    printf("Before adding value inside function num=%d \n",num);    
    num=num+100;    
    printf("After adding value inside function num=%d \n", num);    
}    
int main() 
{    
    int x=100;    
    printf("Before function call x=%d \n", x);    
    change(x);//passing value in function    
    printf("After function call x=%d \n", x);    
    return 0;  
}

Output

Before function call x=100 
Before adding value inside function num=100
After adding value inside function num=200
After function call x=100

Write a program without using library functions ?

Editor — Mon, 12 Jul 2021 20:38:18 +0000

Write a program without using library functions ?

C Standard library functions or simply C Library functions are inbuilt functions in C programming.
The prototype and data definitions of the functions are present in their respective header files, and must be included in your program to access them.
If you want to use printf() function, the header file should be included. For example,

Copy String Manually Without Using strcpy()

In this C Program we have to copy the string without using library functions.

Sample Code

#include 
int main()
{
    char str1[100], str2[100], j;

    printf("Enter the string str1: ");
    scanf("%s",str1);

    for(j = 0; str1[j] != '\0'; ++j)
    {
        str2[j] = str1[j];
    }

    str2[j] = '\0';
    printf("String str2: %s", str2);

    return 0;
}

Output

Enter the String str1: Wikitechy
 String str2: Wikitechy