letsbug Solutions

      Hi everyone in this article we going to make a function to convert binary numbers into decimal numbers.     So before that make sure you are know how to convert the binary numbers to decimal on papers in traditional way. And over here we are just going to implement that logic into code.      And the language is javascript but the logic can be implemented in any language you want. And we are using node.js as javascript runtime. Binary to Decimal In Javascript     code:  const toDecimal = ( binaryNumber ) => {     const digits = String ( binaryNumber ). split ( "" ). reverse ()     let sum = 0     let counter = 1     digits. forEach ( e => {         if ( Number ( e ) !== 0 ) sum = sum + counter         counter = counter * 2     })     return sum } console. log ( toDecimal ( 0 )) console. log ( toDecimal ( 10 )) console. log ( toDecimal ( 11010 )) console. log ( toDecimal ( 1001 )) console. log ( toDecimal ( 101 ))     output:  $ node index.js 0 2 2

      Find Route Between Two Nodes Graph Problem       Hi everyone in this article we are going to see how to solve the problem of finding route between two nodes of a graph.      Before we start let's make sure that you know a little bit about graphs data structure and how to traverse through a graph.  code:  const testG = {     'A' : [ 'B' , 'C' ],     'B' : [ 'D' , 'F' , 'E' ],     'C' : [ 'F' ],     'D' : [],     'E' : [ 'F' ],     'F' : [],     'G' : [] } const path = ( graph , start , end ) => {     if ( start == end ) return true     const queue = [ start ]     const visited = {}     visited[ start ] = true     while (queue.length) {         const node = queue. shift ()         const neighbors = graph [node]         for ( let i = 0 ; i < neighbors.length; i ++ ) {             if ( ! visited[neighbors[i]]) {                 if (neighb

     Javascript Interview Questions 1. What is Rest Parameters?      Answer:            The Rest parameter syntax allows a function to accept indefinite number of arguments as an array. 2. What is Rest Operators?      Answer:            The Rest Operator allows us to call a function and then access those excess arguments as an array. 3. What is Currying functions?      Answer:            Currying is a function that takes one argument at a time and returns a new function expecting the next argument. 4. Immediately invoked functions example:      Answer:            (() => {})() 5.  What is Call()      Answer:            The call() method calls the function with a given this value and arguments provided individually. 6. What is apply()      Answer:            The apply method calls the specified function with a given this value, and arguments provided as an array. 7. What is bind()      Answer:            The bind() method creates a new function that, when called, has its this keyword

    Cyber Offenses And Cyberstalking 1.  Answer the following questions in short. 1. Define Cyber Terrorism.      Answer:            The politically motivated use of computers and information to cause disruption in a nation society 2. What is social engineering?      Answer:            Social engineering is the art of manipulating people, so they give up confidential information. Social engineering is a non-technical strategy used by cyber attackers. It involves human interaction. It uses psychological manipulations to trick uses into making security mistakes or giving away sensitive information. 3. What is cyberstalking?      Answer:            The dictionary meaning of "stalking" is an "act or process of following perey stealthily - trying to approach somebody or something."          Cyberstalking has been defined as the use of information and communications technology, particularly the Internet, by an individual or group or individuals to harass another individua

   Introduction To Cyber Crime And Cyber Security 1.  Answer the following questions in short. 1. What is E-mail spamming?      Answer:            Spam is any kind unwanted, unsolicited digital communication that gets sent out in bulk. Often spam is sent via email, but is can also be distributed via text messages, phone calls, or social media.          E-mail spam is popular but it is used in other media also like Instant messaging Spam, Usenet newsgroups Spam, Web search engine Spam, Spam in blog, wiki Spam, online classified ads Spam, Mobile phone messaging Spam, Internet forum Spam, Social networking Spam, File Sharing network Spam, Video Sharing sites etc. 2. Define cybercrime?      Answer:            Cybercrime is any illegal behaviour, directed by means of electronic operations that target the security of computer system and the data processed by them. 3. What is hacking?      Answer:            Hacking is an act of breaking into a computer and/or network and it is an offense. Ha

     Hello everyone, this article we are going to implement regular expression for email validation in Javascript. Regular Expression is used to validate some value to a specific pattern. If the pattern matches the input value that means it is true else false.     This is not limited to javascript you can implement regular expression in any programming language. The only difference that you will notice is the methods or functions which are built-in the programming language to match these regular expression patterns.     In javascript itself there are many ways to test it. And in this example we will use test() function to test the regular expression against some value pass in as arguments. Regular Expression For Email Validation in Javascript  code: let regx =     / ^ [_A-z0-9-] + ( \.[_A-z0-9] + ) * @ [A-z0-9] + ( \.[A-z0-9-] + ) * ( \.[A-z] {2,3} ) $ / console . log ( regx . test ( "sample@email.com" )) console . log ( regx . test ( "sample.sample@email.subdomain.co

 Wired And Wireless LAN 1.  Answer the following questions in short. 1. What is IEEE standards?      Answer:             The Institute for Electrical and Electronic Engineering developed an Ethernet standard know as IEEE standard 802.3. Ethernet is the most widely-installed Local Area Network technology.            This standard defines rules for configuring an Ethernet network and also specifies how the elements in an Ethernet network interacts with one another. By following IEEE standard, network equipment and network protocol can communicate efficiently. 2. Describe Fast Ethernet.      Answer:              The Fast Ethernet standard (IEEE 802.3u) has been established for Ethernet networks that need higher transmission speeds. This standard raises the Ethernet speed limit from 10 mbps to 100 mbps with only minimal changes to the existing cable structure. Fast Ethernet provides faster throughput for video, multimedia, graphics, Internet surfing and stronger error detection and correct

 Network Connectivity Devices 1.  Answer the following questions in short. 1. What are network connectivity devices?      Answer:            Network Connecting devices includes all computers, peripherals, interface cards and other equipments needed to perform data-processing and communications within the network.          Example: Network Interface Card(NIC), Hub, Switch, Bridge, Router, Gateway. 2. What is active and passive hub?      Answer:            Active hub is a type of hub that takes active participation in data communication within the network/LAN. An active hub is basically a multiport repeater of the class II type, although it is still a physical layer device - it buffers incoming frames and regenerates them, sending the regenerated signal out on all of its ports.          Passive hubs does not provide any additional features except for working just as an interface between the topology. A passive hub simply receives signals on input port and broadcast it on the output port

Network Security  1.  Answer the following questions in short. 1. What is meant by Network security?      Answer:             Network / Computer security consists of the provisions and policies adopted by a network administrator to prevent and monitor unauthorized access, misuse, modification, or denial of a computer network and network-accessible resources.          Network security involves the authorization of access to data in a network, which is controlled by the network administrator. 2. What is plaintext and ciphertext?      Answer:           The plaintext or clear text message can be understood by anybody, (sender, recipients) else who gets access total message.         When a plaintext message is codified using any suitable scheme (encryption), the resulting message is called ciphertext .          The message to be encrypted, know as "plain text"          The output of the encryption process, known as the "ciphertext" 3. What is attack? What are its type?