Whenever React renders the component tree, it looks for changes from the virtual DOM to the actual DOM. If there are changes, it will updat...
In order to ensure events have consistent properties across different browsers, React wraps the browser's native events into "synt...
this.state._____ inside JSX {} inside render if this.state = { name: "Nick" }; then... {this.state.name}
constructor() { super(); this.state = { name: "Vikas" }; }
ReactElement
ReactNode
We can use refs to assign form values to properties on the component object. input: dom element passed in the function <input ref={(in...
We update state by calling this.setState(), this causes our component to re-render. this.setState({showComments:true}) Will only update ...
State handles data changes. State is a JavaScript object that lives inside each component. We can access it via this.state. In React we mod...
Because they're a constructor. It is not a rendered DOM element YET, it just has the capacity to render out a DOM element whenever we p...
Webpack
A virtual DOM object can update much faster than a regular DOM object. A virtual DOM object can't directly affect HTML. A virtual D...
When Component rendering for the second time Virtual DOM checks what element get changed and print the changed element to the page, other e...
When you render a JSX element, every single virtual DOM object gets updated.This sounds incredibly inefficient, but the cost is insignifica...
In React, for every DOM object, there is a corresponding "virtual DOM object." A virtual DOM object is a representation of a DOM ...
When we use our defined components, we can add attributes called props. These attributes are available in our component as this.props and c...
In JSX, you can't use the word class. You have to use className instead because JSX gets translated into JavaScript, and class is a res...
It must have exactly one outermost element. var paragraphs = ( <div id="i-am-the-outermost-element"> <p>I am a par...
You should wrap the multi-line JSX expression in parentheses. This looks strange at first, but you get used to it: ( <a href="ht...
Yes! You can nest JSX elements just like you can do with HTML elements.
JSX is not valid JavaScript. Web browsers can't read it! If a JavaScript file contains JSX code, then that file will have to be compile...
ReactDOM.render(<h1>Hello world</h1>, document.getElementById('app'));
JSX is a syntax extension for JavaScript. Basically HTML that goes into a js file to be compiled into real HTML. A JSX expression must have...
True
React and JSX Transformer <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/react/0.13.1/react....
Following are the advantages/benefits and limitations of React Advantages/benefits: ReactJS can be used on client and server side too. ...
React.js is a JavaScript library developed by engineers at Facebook for building user interfaces. ReactJS allows us to create reusable UI c...
Click here for answers
Improves perception of changes between statistical data graphics Helps tell the story of data changes through time in a meaningful way ...
Dundas BI is a completely separate product with a different codebase and an expanded scope, focusing on self-serve business intelligence, f...
Following are the Key Features and Benefits of Dundas BI Self-Serve Business Intelligence: Dundas BI gives you the ability to create you...
Dundas BI is a state-of-the-art business intelligence platform for building and using interactive dashboards, reports, scorecards, and mor...
Power BI Desktop is a free desktop application you can install right on your own computer. Power BI Desktop works cohesively with the Power...
Power BI provides all sorts of features to help you get started exploring data in a whole new way. Power BI Pro provides all of the same gr...
Here we come with most growing technology related interview questions, the technology is known as Amazon Virtual Private Cloud, we are post...
Puppet is a Configuration Management tool that is used for deploying, configuring and managing servers. It performs the following functions...
Scrum is a simple framework for effective team collaboration on complex projects. Scrum provides a small set of rules that create "jus...
Tools or frameworks that allow source code to be automatically compiled into releasable binaries. Usually includes code-level unit testing ...
LXC - (LinuX Container) is an operating system-level virtualization method that allows multiple isolated Linux systems to run as a single h...
A structured problem‐solving approach that uses a lean tool called the A3 Problem‐Solving Report. The term "A3" represents the pa...
Git is a free, open source distributed version control system tool designed to handle everything from small to very large projects with spe...
Provisioning is the process of preparing new systems for users (in a Continuous Delivery scenario, typically development or test teams). Th...
It is a go-live strategy in which code implementing new features is released to a subset of the production environment but is not visibly, ...
NGINX is open source software for web serving, reverse proxying, caching, load balancing, media streaming, and more. ... In addition to its...
Acceptance Testing is typically high-level testing of the entire system carried out to determine whether the overall quality of both new an...
Chef is an automation tool that provides a way to define infrastructure as code. Infrastructure as code (IAC) simply means that managing in...
You can deploy code to production without releasing Release is to make functionality available to end users
Collaboration Breakdown the barriers Work as one team end to end Treat Infrastructure as code Support business and IT agility Autom...
1. Lack of resources (Developers) 2. Developer are so costly due to lack of resources 3. Difficult to hire good DevOps developer. 4. Dev...
Elastic Block Store aka EBS is a type of block storage system that provides persistent block storage volumes for use with EC2.
It is a software distribution model where applications are hosted by a vendor and made available to customers over the Internet
By using automated testing, continuous integration, continuous delivery and automated infrastructure.
It is a software development methods in which requirements and solutions evolve through collaboration between self-organizing, cross-functi...
Below are the steps of build a custome VPC: 1. Create a VPC 2. Create subnets 3. Create an internet gateway (IGW) 4. Attach the new IG...
AWS CodeCommit: AWS CodeCommit is a fully-managed source control service that makes it easy for companies to host secure and highly sca...
Ans: This diagram is showing DevOps as the intersection of development (software engineering), technology operations and quality as...
1. Culture. 2. Organization (style including roles). 3. Processes. 4. Tools.
AWS DevOps Interview Question: What are the Advantage/Benefits of using AWS for DevOps? Why use AWS for DevOps? Ans: Below are the Beni...
Speed: Move at high velocity so you can innovate for customers faster, adapt to changing markets better, and grow more efficient at dr...
DevOps is the combination of cultural philosophies, practices, and tools that increases an organization’s ability to deliver applications a...
Here we come with most growing technology related interview questions, the technology is known as Amazon Virtual Private Cloud, Today is 18...
Yes. There are multiple options for your resources within a VPC to communicate with Amazon S3. You can use VPC Endpoint for S3, which makes...
You will need to disable NAT-T on your device. If you don’t plan on using NAT-T and it is not disabled on your device, we will attempt to e...
When you launch an Amazon EC2 instance within a VPC, you may optionally specify the primary private IP address for the instance. If you do ...
The minimum size of a subnet is a /28 (or 14 IP addresses.) for IPv4. Subnets cannot be larger than the VPC in which they are created.
Currently you can create 200 subnets per VPC. If you would like to create more, please submit a case at the support center.
No. To change the size of a VPC you must terminate your existing VPC and create a new one.
VPN connection-hours are billed for any time your VPN connections are in the "available" state. You can determine the state of a ...
Yes. You can assign one or more secondary private IP addresses to an Elastic Network Interface or an EC2 instance in Amazon VPC. The number...
You can assign any IP address to your instance as long as it is: Part of the associated subnet's IP address range Not reserved by A...
Default VPCs are assigned a CIDR range of 172.31.0.0/16. Default subnets within a default VPC are assigned /20 netblocks within the VPC CID...
You assign a single Classless Internet Domain Routing (CIDR) IP address block when you create a VPC. Subnets within a VPC are addressed fro...
You will use the public IP address of your NAT device.
Yes, you will need to enable NAT-T and open UDP port 4500 on your NAT device.
Amazon does not enforce any restrictions on VPN throughput. However, other factors, such as the cryptographic capability of your customer g...
Establishing a hardware VPN connection between your existing network and Amazon VPC allows you to interact with Amazon EC2 instances within...
The DescribeVPNConnection API displays the status of the VPN connection, including the state ("up"/"down") of each VPN ...
ClassicLink does not change the access control defined for an EC2-Classic instance through its existing Security Groups from the EC2-Classi...
Traffic from an EC2-Classic instance can only be routed to private IP addresses within the VPC. They will not be routed to any destinations...
ClassicLink cannot be enabled for a VPC that has a Classless Inter-Domain Routing (CIDR) that is within the 10.0.0.0/8 range, with the exce...
There are two types of VPN connections that you can create: statically-routed VPN connections and dynamically-routed VPN connections. Custo...
IPsec is a protocol suite for securing Internet Protocol (IP) communications by authenticating and encrypting each IP packet of a data stre...
A hardware VPN connection connects your VPC to your datacenter. Amazon supports Internet Protocol security (IPsec) VPN connections. Data tr...
Instances without public IP addresses can access the Internet in one of two ways: Instances without public IP addresses can route their tr...
You can use public IP addresses, including Elastic IP addresses (EIPs), to give instances in the VPC the ability to both directly communica...
No
An Amazon VPC router enables Amazon EC2 instances within subnets to communicate with Amazon EC2 instances in other subnets within the same ...
Not
You can have: Five Amazon VPCs per AWS account per region Two hundred subnets per Amazon VPC Five Amazon VPC Elastic IP addresses per ...
Yes. You can use the AWS Management Console to manage Amazon VPC objects such as VPCs, subnets, route tables, Internet gateways, and IPSec ...
Yes. You may create a default route for each subnet. The default route can direct traffic to egress the VPC via the Internet gateway, the v...
Yes. You can create route rules to specify which subnets are routed to the Internet gateway, the virtual private gateway, or other instance...
The ClassicLink connection will not persist through stop/start cycles of the EC2-Classic instance. The EC2-Classic instance will need to be...
The EC2-Classic instance does not become a member of the VPC. It becomes a member of the VPC Security Group that was associated with the in...
In order to use ClassicLink, you first need to enable at least one VPC in your account for ClassicLink. Then you associate a Security Group...
Amazon Virtual Private Cloud (VPC) ClassicLink allows EC2 instances in the EC2-Classic platform to communicate with instances in a VPC usin...
Bandwidth between instances in peered VPCs is no different than bandwidth between instances in the same VPC. Note: A placement group can sp...
No. Traffic between instances in peered VPCs remains private and isolated – similar to how traffic between two instances in the same VPC is...
No. VPC peering connections do not require an Internet Gateway.
No. Peered VPCs must have non-overlapping IP ranges.
No. “Edge to Edge routing” isn’t supported in Amazon VPC. Refer to the VPC Peering Guide for additional information.
No. You can attach and detach secondary interfaces (eth1-ethn) on an EC2 instance, but you can’t detach the eth0 interface.
Yes, however, this is not a use case best suited for multiple interfaces. Instead, assign additional private IP addresses to the instance a...
Network interfaces can only be attached to instances in the same VPC as the interface.
Network interfaces can only be attached to instances residing in the same Availability Zone.
The total number of network interfaces that can be attached to an EC2 instance depends on the instance type. See the EC2 User Guide for mor...
Yes, assuming the owner of the other VPC accepts your peering connection request.
No. Peering connections are only available between VPCs in the same region.
AWS uses the existing infrastructure of a VPC to create a VPC peering connection; it is neither a gateway nor a VPN connection, and does no...
Yes
If your AWS account has a default VPC, any IAM accounts associated with your AWS account use the same default VPC as your AWS account.
Yes, however, we can only enable an existing account for a default VPC if you have no EC2-Classic resources for that account in that region...
The simplest way to get a default VPC is to create a new account in a region that is enabled for default VPCs, or use an existing account i...
No. Transitive peering relationships are not supported.
No. Either side of the peering connection can terminate the peering connection at any time. Terminating a peering connection means traffic ...
Yes, but once deleted, it’s gone. Your future instance launches will be placed in your remaining default subnet(s).
Yes. Contact AWS Support if you've deleted your default VPC and want to have it reset.
No. Default VPCs are attached to the Internet and all instances launched in default subnets in the default VPC automatically receive public...
Yes. You can reserve an instance in Amazon VPC when you purchase Reserved Instances. When computing your bill, AWS does not distinguish whe...
Yes, however, an instance launched in a VPC using an Amazon EBS-backed AMI maintains the same IP address when stopped and restarted. This i...
Yes, you may use Amazon EBS snapshots if they are located in the same region as your VPC. More details are available in the Amazon EC2 Regi...
See Differences between EC2-Classic and EC2-VPC in the EC2 User Guide.
No. You can use the AWS Management Console, AWS EC2 CLI, or the Amazon EC2 API to launch and manage EC2 instances and other AWS resources i...
Yes. To launch into nondefault subnets, you can target your launches using the console or the --subnet option from the CLI, API, or SDK.
Yes. To launch an instance into nondefault VPCs you must specify a subnet-ID during instance launch.
The Amazon EC2 console indicates which platforms you can launch instances in for the selected region, and whether you have a default VPC in...
If your AWS account was created after March 18, 2013 your account may be able to launch resources in a default VPC. See this Forum Announce...
When you launch resources in a default VPC, you can benefit from the advanced networking functionalities of Amazon VPC (EC2-VPC) with the e...
A default VPC is a logically isolated virtual network in the AWS cloud that is automatically created for your AWS account the first time yo...
Yes. Cluster instances are supported in Amazon VPC, however, not all instance types are available in all regions and Availability Zones.
One default subnet is created for each Availability Zone in your default VPC.
The default VPC CIDR is 172.31.0.0/16. Default subnets use /20 CIDRs within the default VPC CIDR.
You can have one default VPC in each AWS region where your Supported Platforms attribute is set to "EC2-VPC".
Yes
You can run any number of Amazon EC2 instances within a VPC, so long as your VPC is appropriately sized to have an IP address assigned to e...
Yes. DescribeVolumes() will return all your EBS volumes.
Yes. DescribeInstances() will return all running Amazon EC2 instances. You can differentiate EC2-Classic instances from EC2-VPC instances b...
When you create a subnet you must specify the Availability Zone in which to place the subnet. When using the VPC Wizard, you can select the...
Security groups in a VPC specify which traffic is allowed to or from an Amazon EC2 instance. Network ACLs operate at the subnet level and e...
Amazon EC2 security groups can be used to help secure instances within an Amazon VPC. Security groups in a VPC enable you to specify both i...
No. An Internet gateway is horizontally-scaled, redundant, and highly available. It imposes no bandwidth constraints.
When you launch an Amazon EC2 instance you must specify the subnet in which to launch the instance. The instance will be launched in the Av...
Yes
You can use AMIs in Amazon VPC that are registered within the same region as your VPC. For example, you can use AMIs registered in us-east-...
Yes.
Amazon VPC is currently available in multiple Availability Zones in all Amazon EC2 regions.
Yes. You can use the Amazon VPC Flow Logs feature to monitor the network traffic in your VPC. Amazon VPC & EC2
Ping (ICMP Echo Request and Echo Reply) requests to the router in your VPC is not supported. Ping between Amazon EC2 instances within VPC i...
Yes. If an Internet gateway has been configured, Amazon VPC traffic bound for Amazon EC2 instances not within a VPC traverses the Internet ...
Yes
Stateful filtering tracks the origin of a request and can automatically allow the reply to the request to be returned to the originating co...
Amazon VPC enables you to build a virtual network in the AWS cloud - no VPNs, hardware, or physical datacenters required. You can define yo...
Amazon VPC comprises a variety of objects that will be familiar to customers with existing networks: A Virtual Private Cloud (VPC): A l...
