Web Technology Experts Notes

Question: What is Azure Blob storage?
Azure Blob storage is a service that stores unstructured large data in the cloud in form of objects/blob.
Blob storage can store any type of file like image, video OR text etc.
Stored data can be accessed through HTTP or HTTPS.

Question: What is Blob?
It is large file like an image, video or binary data.

Question: Why Blob Storage are used?

Streaming Audio/Video.
Storing data for backup and restore.
Store heavy data like images, audio and videos.
Access the data in browser.
Storing files for distributed access.

Question: What is structure of Blob storage?
An account can have one OR More container.
User can store the data in container.
For Example:

One Account 
    Movies (Container 1)
        movie1.mp4 (Blob data)
        movie2.mp4 (Blob data)
        movie3.mp4 (Blob data)

    videos (Container 2)
        video1.mp4 (Blob data)
        video1.mp4 (Blob data)
        video1.mp4 (Blob data)

    photos (Container 3)
        photo1.jpg (Blob data)
        photo2.jpg (Blob data)
        photo3.jpg (Blob data)
        photo4.jpg (Blob data)

Question: How to get azure client Libraries (using composer)?

1. Create a folder where you want to download the library.
Install composer (If not) php -r "readfile('https://getcomposer.org/installer');" | php

Create a composer.json (with following data)

{
   "require": {
     "microsoft/windowsazure": "^0.4"
   }
 }

Download the library with following command.
```
php composer.phar install
```

Question: Give a tutorial from where i can do list/add/update/delete the azure blob data?
https://docs.microsoft.com/en-us/azure/storage/storage-php-how-to-use-blobs

Question: In how many programming language code is available?

.NET
Java
Node.js
C++
Python
P?HP
Ruby
iOS
Xamarin

Question: What is mount in linux?
Mounting a filesystem means making the particular filesystem accessible.
When mounting a filesystem it does not matter if the filesystem is a hard disk partition, CD-ROM, floppy, or USB storage device.

Question: Differences between Azure Block Blob and Page Blob?
Block blobs are for your discrete storage objects like jpg's, log files, etc.
Page blobs are for random read/write storage, such as VHD's. Max size 1TB.

Question: What is the maximum length of an Azure blob name?
1024 max character.

Tuesday, 25 April 2017

React JS Interview Questions and Answers

Question: What is ReactJS?
React is front end library developed by Facebook.

Question: Why ReactJS is used?
React is used to handle the view part of Mobile application and Web application.

Question: Does ReactJS use HTML?
No, It uses JSX which is simiar to HTM.

Question: When ReactJS released?
March 2013

Question: What is current stable version of ReactJS?
Version: 16.2.0
Release on: November 28, 2017

Question: What is Repository URL of ReactJS?
https://github.com/facebook/react

Question: What are the life Cycle of ReactJS?

Initialization
State/Property Updates
Destruction

Question: What are the feature of ReactJS?

JSX: JSX is JavaScript syntax extension.
Components : React is all about components.
One direction flow: React implements one way data flow which makes it easy to reason about your app

Question: What are the Advantages of ReactJS?

React uses virtual DOM which is JavaScript object. This will improve apps performance
It can be used on client and server side
Component and Data patterns improve readability.
Can be used with other framework also.

Question: How to embed two components in One component?

import React from 'react';
class App extends React.Component {
   render() {
      return (
         <div>
            <Header/>
            <Content/>
         </div>
      );
   }
}

class Header extends React.Component {
   render() {
      return (
         <div>
            <h1>Header</h1>
         </div>
      );
   }
}

class Content extends React.Component {
   render() {
      return (
         <div>
            <h2>Content</h2>
            <p>The content text!!!</p>
         </div>
      );
   }
}

export default App;