Interview Questions.

Technical Interview Questions and Answers [Updated]


Technical Interview Questions and Answers [Updated]

There may be no person in this techy world who has in no way recognize approximately networking and its importance. Network engineering is one of the trendiest jobs of out instances.

Earlier, if a person wishing to appear for an interview wishes to cautiously go through all the books and materials to be had page by way of web page. But the internet, a networking gadget has made it all so easy. Regardless of whether or not you're a brisker or an experienced person, be prepared to face a few fundamental networking questions in case you're making ready for a networking interview.

Top Technical Interview Questions and Answers

This article covers Technical Interview questions and solutions from the fundamental networking, C, C++, Java, and OS era.

Networking Interview Questions

Question: What is Computer Networking?

Answer: A computer community is a set of connected computers for aid sharing purposes. Today's most commonplace device shared is an Internet connection.

Question: Difference among communication and transmission?

Answer: Transmission is a bodily data manner that involves troubles including bit polarity, synchronization, clock, etc. Communication way complete data alternate among  communique networks.

Question: What is a gateway?

Answer: A gateway is a Node in a community. They accept a package deal formatted for a protocol and before resending it, they convert it to a package formatted for some other protocol.

Question: What is Network Mask?

Answer: A masks is a bit pattern for identifying the cope with of the network/subnet. The IP deal with contains two components: the cope with of the network and the cope with of the host.

The IP addresses are categorised into distinctive lessons which are used to pick out the network deal with

Question: What are the variations among TCP/UDP?

Answer: TCP (Transmission Control Protocol): TCP is a link-primarily based protocol. A link may be made among client and server and from then on some records can be despatched alongside the path.

When you ship a message at the side of a TCP socket, you'll get it if the connection fails absolutely. If it gets misplaced along the way, the customer can re-call for the missing part. It method integrity; facts will now not be compromised.

UDP(User Datagram Protocol): UDP is a connectionless protocol. With UDP you ship messages (packets) across the network in chunks.

When you send a message, you don’t know if it’ll get there - it may wander off at the manner. If you send  messages out, you don’t know what order they’ll arrive in.

Question: Compare IPv4 and IPv6 protocol?

Answer: Ipv4 and Ipv6 are net protocols which are implemented to the community layer. Ipv4 is currently the maximum usually used protocol and Ipv6 is the following technology net protocol.

Ipv4 is the fourth model of the Internet protocol which makes use of 32-bit addressing whilst Ipv6 is a 128-bit protocol addressing the subsequent era of the Internet.

Ipv4 makes 4,294,967,296 specific addresses whilst Ipv6 may have 340-undecillion particular addresses.

Ipv4 Address Notation:, Eight groups of hexadecimal quartets separated with the aid of colons among them represent IPv6 addresses.

Question: How URL is processed right into a browser?

Answer: There is no actual answer to this query, despite the fact that here are the steps of the way a URL is processed:

To find the URL IP deal with, the browser contacts the DNS server.

DNS returns the website's IP cope with.

The client opens the TCP port eighty internet server hyperlink.

The browser fetches the HTML code of the web page requested.

In the show window, the browser renders the HTML.

Question: What are the special Routing protocol?


Border Gateway Protocol

Routing Information Protocol

Open Shortest Path First

Question: What is MAC cope with?

Answer: In a network, MAC address is the precise identification cope with for a tool. Normally the MAC cope with is stored on the community adapter card in ROM.

Question: What are the distinctive varieties of networking gadgets?


1. Hub

The community hub is a node machine that links a couple of computer systems at one factor Centralized conversation gadgets are the concentrators, connected in the center of the famous person hyperlink network. All devices which are connected to a community hub percentage the bandwidth this is to be had equally.

2. Repeater

Repeater is digital gadgets used to avoid distortion in sign transmission. A repeater gets the sign in the network, regenerates the original bit then transfers it thru the same channel to avoid distortion.

Three. Router

The router is a machine for linking one network (LAN, WAN) to any other (LAN, WAN) community. The router selects the most appropriate course for transmitting the signal relying on the area of the sender and receiver.

4. Gateways

Gateways are used to convert one format to every other layout in a network. If  components of the equal network have one of a kind conversation codecs connecting them requires a gateway. They operate in all seven layers of the OSI version.

5. Bridges

Network bridges are smart gadgets that procedure and report sign visitors information between devices in networks. Then the bridge makes use of this records to decide the most green path among a transmitting and receiving device for records switch without having to ship it to any computer in the network.

Java Interview Questions

Question: What is JAVA?

Answer: Java is an object-oriented programming language. Java was designed for virtual client gadgets but was later moved to the Internet. Now Java is a extensively-used programming language for internet. Java-advanced software program can run on any of the arena's hardware or operating structures.

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Question: Application where it's miles viable to develop in Java?


Standalone Applications: Under the computer's operating gadget, a standalone software is a application jogging on our nearby pc much like a C or C++ software.

Applets: An applet is a small software that flies over the Internet and runs on the consumer laptop via a Java-well suited net browser like Internet Explorer or Netscape Navigator.

An applet is saved in the webserver and travels across the network and downloads it in the patron device dynamically whilst a consumer computer requests it. Only via embedding it into an HTML file, together with a sound report or picture document or video clip, can Applet be accomplished.

Distributed Applications: To reap distributed software in Java application, Java divides packages into small organizations which could run on separate machines. The items used can engage with each other in those programs. These systems are called Distributed applications

Web Applications: These are a program going for walks on internet servers. Web servers manner these programs whilst we look for a website using its URL within the browser. The internet browser sends a request for that unique internet site to the webserver. After going for walks this system the server sends the end result to the purchaser.

Question: Explain Java language specification?

Answer: The Java language specification is a set of regulations that must follow when writing a Java application, that consists of Java programming language syntax and semantics. The specs include API, JDE, IDE.

API: The Application Program Interface (API) is still increasing specification that carries predefined training and interfaces for developing Java programs.

JDK: Java Development Kit (JDK) is used for developing take a look at Java programs, which contains a separate software that invokes every command line.

IDE: Integrated Development Environment (IDE) includes a graphical user interface that enables Editing, compiling, constructing, debugging, and on line assist. Simply enter the source code in a single window or open an existing record in a browser, then click a button, menu object, or feature key to assemble and run the program.

Question: What is RMI and RMI architecture?

Answer: Remote Method Invocation (RMI) permits executing java object on one machine and invoking the method of executing a Java item on a one-of-a-kind system.

RMI structure includes 4 layers:

Application layer: incorporates the actual item definition.

Proxy layer: consists of stub and skeleton.

Remote Reference layer: Sets the byte move from the transportation layer and passes it to the proxy layer.

Transportation layer: Responsible for the real communique among system to system.

Question: What is Servlet chaining?

Answer: Servlet chaining permits one to participate in one or greater servlets for servicing a unmarried request. Through servlet chaining, the output of 1 servlet might be piped to the enter of the following servlet. The cycle keeps earlier than reaching the ultimate servlet. The output would then be returned to the patron.

Question: What is connection pooling?

Answer: Opening a server hyperlink with servlets is a chief bottleneck due to the fact for every web page query new connection is hooked up, that's time-consuming.

With a connection pool, we are able to only replica the sources that we need to replicate rather than the entire servlet and also it is able to manipulate the scale of the pool.

Question: What are cookies?

Answer: Cookies are a tool used by a servlet to keep a purchaser keeping a small amount of consumer-associated kingdom statistics. Simply, small data despatched to a browser by means of an internet server that can be study returned from that browser later

Question: How to track a consumer?

Answer: There are  approaches in tracking customer from servlet API, they are:

Using session monitoring


Question: What is JDBC?

Answer: JDBC is a sequence of SQL statements in Java API. This API consists of a fixed of training and interfaces that allow programmers to write down natural packages for Java Database.

Question: What is the difference between JDBC and ODBC?


JDBC - Java Database Connectivity, ODBC- Open Database Connectivity

OBDC is for Microsoft and JDBC is for Java programs

As ODBC uses C interface it may’t be used without delay with Java

For simple queries, ODBC blends easy and advanced functionality and has complex options. But JDBC is designed to hold matters simple and permit advanced abilities whilst vital

ODBC calls for manual installations whilst the JDBC code is routinely installable.

C Programming Interview Questions

Question: What is C language?

Answer: The C programming language is a standardized programming language evolved for use at the UNIX working machine. C is the most commonplace programming language for writing machine software, even though it is also used for writing programs.

Question: What are the one of a kind garage classes in C?

Answer: C has 3 storage kinds: automatic static and allotted. Variable with block variety and automatic processing period with out a static specifier. Block scope variables and static specifier variables have static scope. There is also a dynamic scope for worldwide variables (i.E., file scope) without or with the static specifier. Memory received from calls to malloc( ), alloc( ) or realloc( ) belongs to the memory magnificence allotted.

Question: What is the output of printf("%d")?

Answer: If we write printf("%d,"x); which means that the x price might be printed by using the compiler. But as right here, after %d there's nothing, so the compiler will show garbage cost inside the output window.

Question: What is the distinction between printf( ) and sprintf( ) ?

Answer: Sprintf ( ) writes the individual array facts whilst printf(...) writes the same old output gadget facts.

Question: Can you tell how to check whether a linked list is circular?

Answer: Create  factors and set them both on the begin of the list, application:

while (pointer1) {
pointer1 = pointer1->next;
pointer2 = pointer2->next;
if (pointer2) pointer2=pointer2->next;
if (pointer1 == pointer2) {
print ("circular");

Question: What is hashing?

Answer: Hashing approach grinding up, and that's what hashing is all about. A hashing algorithm's center is a hash characteristic that takes your excellent, clean records and grinds it into a random-looking whole.

The idea at the back of hashing is that a few records either does now not have an inherent order (together with pix) or are pricey to examine. If the records does no longer have an underlying order, evaluation searches can't be performed.

Question: Explain the difference between strings and individual arrays?

Answer: A fundamental difference is: string will have static garage length, whilst string will not have static storage length as a person set unless the static keyword is used to indicate explicitness.

The multi-byte man or woman series we generally call string is used to initialize a static space period variety. The width of this set is sufficient to contain those characters in addition to the terminating NUL code.

It isn't distinctive what occurs if this array, i.E., string, is modified.

The same memory discipline may be shared by means of  strings of the same price.

Question: Why n++ executes quicker than n+1 ?

Answer: To perform the increment operation, the expression n++ calls for a single system guidance inclusive of INR, whilst n+1 needs more commands.

Question: What is the cause of important( ) characteristic?

Answer: The important ( ) characteristic invokes different functions inside it. It is the primary characteristic to be written when jogging a software.

It is a starting characteristic

It returns an int cost to the surroundings that referred to as the program

Recursive calling for fundamental ( ) is likewise enabled

It is a user-described function

Execution of this system ends when the principle ( ) function closes.

It has  arguments 1) argument matter and a couple of) argument vector

Question: What is the distinction among %d and %*d in c language?

Answer: The % d offers the variable's authentic price and the %* d gives the variable's call.


int a=10,b=20;

Here end result for the first printf might be 10,20 and the end result for the second one printf supply memory allocation that can say 1760.

C++ Interview questions

Question: What is C++?

Answer: C++ is an item-orientated programming language. C++ keeps nearly all factors of the C language, simplifying memory control and adding a couple of functions. C++ keeps C functions that allow get admission to to low-level memory, but additionally affords the programmer with new tools to enhance memory control.

Question: What is a constructor?

Answer: A constructor is used to developing and initialize an object. It additionally generates a virtual characteristic vtable. It's unique in a class from different procedures.

What is a constructor? - Technical Interview Questions

Question: What is inheritance?

Answer: Inheritance allows one magnificence to reuse another magnificence' country and movements. The derived elegance inherits and expands the base elegance' residences and technique implementations by editing strategies and including extra residences and techniques.

Question: What is a class?

Answer: A class is an extended definition of a statistics structure: it may comprise each information and features in preference to preserving best information.

Question: How do  that your elegance desires a digital destructor?

Answer: If we've even one virtual function inside the class, we want to make a virtual destructor. This will allow you to remove a dynamic item from a base class object via a caller.

Question: What is the distinction among realloc() and unfastened()?

Answer: The free subroutine eliminates a memory block that the malloc subroutine had previously reserved. The undetermined end result happens if the pointer parameter is not a valid pointer. If the Pointer parameter is a null value, no movement will occur.

The realloc subroutine adjusts the size of the reminiscence block relating to the quantity of bytes described by the Size parameter by way of the Pointer parameter and returns a new pointer to the row. The pointer defined via the Pointer parameter have to were generated with the subroutines of malloc, calloc, or reallocation and not dealing with the subroutines of unfastened or reallocation.

Question: Write a characteristic which can opposite a linked-listing?


void reverselist(void)
head->next = 0;
tail->next = head;
node* pre = head;
node* cur = head->next;
node* curnext = cur->next;
head->next = 0;
cur-> next = head;
for(; curnext!=0; )
cur->next = pre;
pre = cur;
cur = curnext;
curnext = curnext->next;
curnext->next = cur;

Question: What is the distinction among C++ & Java?




Classes and functions can be templated.

Classes and methods can be genericized

Parameters can be any type or integral value.

Reference type parameter only

For each type parameter, separate class or function copies are likely to be created when compiled.

For all types of parameters, there is only one type of class or function is compiled

The templated class or a function's source code must be included, in order to use it

Signature of the class or function from a

compiled class is sufficient to use it.

Templates can be specialized

Cannot be specialized (generic)

The bounding type parameter is not allowed but is supported by metaprogramming.

Supports upper and lower bounding of category parameters with "extends" and “super”

For static methods and variables, the type parameter of the templated class can be used

For static methods and variables, the form parameter of the templated class can not be used.

There is no sharing of static variables between classes of different types of parameters.

Static variables are shared among instances of different type class parameters

Question: What is RTTI?

Answer: Runtime type identification (RTTI) allows you to discover an object's dynamic shape whilst you only have a pointer or a base type reference. RTTI is the authentic way to discover the sort of an item in standard C++ and to transform a reference or pointer type.

Question: How do virtual functions paintings in C++?

Answer: A virtual function is predicated on a digital table or board. If any of a category's features are taken into consideration virtual, a v-desk is constructed that stores addresses of this class's digital features. The compiler additionally provides in all such instructions a secret vptr variable that points to that class's vtable.

If a digital feature within the derived elegance is not overridden, the vtable in the derived class must save the function address in its determine magnificence.

Operating gadget Interview Questions:

Question: What is an working device (OS)?

Answer: An Operating System (OS) is a pc user-hardware interface. There are  major functions of running systems. One is to make sure that a pc gadget works properly. Another is that it offers a framework for gadget development and implementation.

Some famous Operating Systems consist of Linux, Windows, OS X, VMS, OS/four hundred, AIX, z/OS, and so on.

Question: What are the benefits of a multiprocessor system?

Answer: There is a vast boom in throughput with an improved number of processors. However, due to the fact they are able to percentage assets, it may shop more money. Finally, there may be also an boom in typical performance.

Question: What is SMP?

Answer: SMP is a brief shape of Symmetric Multi-Processing. It's the maximum famous multi-processor tool kind. Each processor runs an same replica of the operating machine in this device and those copies speak with every different as needed.

Question: What are the sorts of Operating System?


Batch operating system

Time-sharing running systems

Distributed operating System

Network working System

Real-Time Operating System

Question: What is the excellent page size when designing an operating device?

Answer: Paging length varies from device to system. In order to create a suitable page length, there are various elements to do not forget, including web page desk, paging time, and its effect on the general operating gadget overall performance.

Question: What is caching?

Answer: Caching is the storage for constrained data and strategies the use of a vicinity of fast memory. Because of its excessive get right of entry to pace, cache memory is usually very effective.

Question: Explain why Ubuntu OS is safe and now not affected by viruses?


It does no longer receive malicious emails and content, and many security assessments might be accomplished earlier than any email is opened through users.

Ubuntu uses Linux, i.E. A exceptional-cozy O.S device

Unlike different O.S, countless Linux customers may be able to see the code at any time and solve the problem if any.

Question: What is the function of paging?

Answer: Paging is a memory management machine that permits a manner to be non-contiguous within the physical cope with area. This gets rid of the sizeable trouble of fitting varied chunks of memory inside the backup save.

Question: What is the Translation Lookaside Buffer (TLB)?

Answer: In a cached device the base addresses of the last couple of referenced pages are saved in registers called the TLB which helps with quicker research. TLB includes the maximum recently used page table entries. Typically, every virtual memory link requires two accesses to bodily memory-one to get the best page desk access and one to get the requested information. It limits the use of TLB in-between to simply one bodily reminiscence get right of entry to in TLB-hit instances.

Question: How are server systems classified?

Answer: It is feasible to identify database structures as either computer server systems or record server systems. In the first instance, customers are supplied with an utility to submit requests for action. In the second one case, there are provisions for developing, having access to, and updating documents for clients.