Sunday, July 19, 2020

Fork Commit

1. All Changes

Move to stage

2. All commits

Enter Commit Subject

Click on commit

3. Push

Monday, May 18, 2020

Webpack file loaders to use pdf and image from outside project folder in react

After changes done in webpack.config file just re-run by npm start the project so that webpack-dev-server will start with new changes.

We can access image files or pdf files located inside project or outside project in react Project

to access the pdf files u need to have pdf file loader in webpack.config file

import Pdf from './sample.pdf'; Open Pdf files

To access image files u need to have image file loader in webpack.config file

import image from './sample.pdf'; "

Friday, March 27, 2020

spawn git error while npm install

Install git in the system.

Then try npm install.

Thursday, March 19, 2020

React Js and Redux Questions

# React:

React is javascript front end library developed by facebook.
React follows uni-directional data flow.
In react everything is component and it divides ui in independent piece of code.

# Why to use React Or Features Of React?

We can make Reusable Components.
You can re-use components anywhere you need. As a result, (1) your app has consistent look and feel, (2) code re-use makes it easier to maintain and grow your codebase, and (3) it is easier to develop your app. eg. Forms , Wizards
Virtual DOM: Any view changes are first reflected to virtual DOM, then an efficient diff algorithm compares the previous and current states of the virtual DOM and calculates the best way (minimum amount of updates needed) to apply these changes. Finally those updates are applied to the DOM to ensure minimum read/write time. This is the main reason behind React’s high performance
Improved performance: React uses virtual DOM, which makes web applications perform faster. Virtual DOM compares its previous state and updates only those components in the real DOM, whose states have changed, rather than updating all the components — like conventional web applications.
Unidirectional data flow: React follows a unidirectional data flow. This means that when designing a React app, we often nest child components within parent components. And since the data flows in a single direction, it becomes easier to debug errors and know where the problem occurs in an application at the moment.
Easy creation of dynamic applications as it provides less coding and provides more functionality, whereas, with JavaScript applications, code tends to get complex very quickly.
Dedicated tools for easy debugging: Facebook has released a chrome extension that we can use to debug React applications. This makes the process of debugging React to web applications faster and easier.

# State and props:

State are the actual javscript objects which stores the properties and behaviours of the component.
State values are passed down from parent components to child components in the form of props.
props are the way of communication between the components.

# Redux thunk :

Used to handle asyn actions.
Redux thunk is a middleare that lets u call action creators that returns functions instead of an action object.
That function receives the store's dispatch method, which is then used to dispatch regular synchronous actions inside the body of the Function once the asynchronous operations have completed.

# Real Dom:

Abstraction of html code.
Html element becomes node in dom.
Creates a new dom when html element updates.
Slow.
DOM manipulation is very expensive
Too much of memory wastage.

# Virtual Dom:

Lightweight Javascript object.
Abstraction of Real dom.
React Element becomes node in v dom.
Updates the JSX if element updates.
Fast.
DOM manipulation is very easy
No memory wastage.

# References in react:

It is an attribute which helps to store a reference to a particular React element or component.
It is used to return references to a particular element or component returned by render().

# Fetch

Fetch has no url in request object.
Fetch request function includes the url as parameter.
Fetch request is ok when response object contains the ok property

# Axios:

Axios has url in request object
Axios request function does not includes the url as parameter.
Axios request is ok when status is 200

#Redux:

Redux is the applications state management library which stores the entire state of an applications in the single store.

# Switch:

Switch returns only the first matching route rather than all matching routes.

# Link:

Link is your replacement for anchor tags.

Javascript Questions

# prototype:

The JavaScript prototype property allows you to add new properties and methods to object constructors.
function person(first) { this.fName= first}
person.prototype.nationality = "English";

# promises:

promises are used to handle asynchronous operations in JavaScript.
var promise = new promise(function(resolve, reject) {reject('promise Rejected') })
promise.then(function(successMessage) { }).catch(function(errorMessage) { });

Definition: Helps you run functions asynchronously, and use their return values (or exceptions) but only once when executed.
Not Lazy
Not cancellable( There are promise libraries out there that support cancellation, but ES6 promise doesn't so far). The two possible
Cannot be retried(promises should have access to the original function that returned the promise to have a retry capability, which is a bad practice)
Decisions are
- resolve
- Reject

# Observables

Helps you run functions asynchronously, and use their return values in a continuous sequence(multiple times) when executed.
By default, it is Lazy as it emits values when time progresses.
Has a lot of operators which simppfies the coding effort.
One operator retry can be used to retry whenever needed, also if we need to retry the observable based on some conditions retryWhen can be used.

# Hoisting:

a variable can be used before it has been declared.

# Closure:

Inner function can have access to the outer function variables as well as all the global variables. Lets suppose we two function A, B and function B is the child function of function A. We have variable inside the function A and when we access the function A variable inside the function B then there closur gets created.Below example creates and using the closure.

This function can be better represented by using closures

function A() {
    var count = 10;
    return function displayGreet() {
        console.log(count);
    };
}

// Generate the closure
	var B= A();

// Use the closure
	B();

# Shift method:

shift() method take the first element off of the given array and returns it.

# pop method:

pop() method take the last element off of the given array and returns it.

# Delete operator:

The delete keyword is used to delete the key as well as its value of the given object properties.

# unshift method:

The unshift method is used to add or append one or more elements to the begining of an Array.

# push method:

The push method is used to add or append one or more elements to the end of an Array.

# What are escape characters :

Is used to display the special characters in the string .

# What is the use of type of operator:

is an operator which is used to return a string description of the type of a variable.

# What is variable typing:

Variable typing is used to assign a number to a variable and then assign string to the same variable.

# Assign value to object properties:

obj.name="AK"

# append value to an array without using push :

arr[arr.length]=value;

# for-in loop:

for-in loop is used to loop through the javascript object.

#for loop :

for loop is used to loop through the javascript array.

# call:

arguments are passed as individually like object.mymethod.call(object,arg1,arg2,arg3)

# apply:

arguments are passed in the form of array like object.mymethod.call(object,array)

# Object.values

this method returns an array of values form the given object properties

#Object.keys :

this method returns an array of keys form the given object properties

# Functional Components

A functional component is just a plain JavaScript function which accepts props as an argument and returns a React element.

Functional component is easy to read and test.

Functional component ends up with very less code.

You cannot use setState() and Lifecycle Methods in your component.

Functional component is state less component.

# Class Components

Class component requires you to extend from React.Component and create a render function which returns a React element..

Class component will have the State and Life Cycle Methods.

Class compoenent ends with more code as compared to functional components.

# let

block scoped eg. if-block.

Reference errors if let causes errors

Variable declared with let will not affect the value of variable defined outside if block.

var a=11; function test(){ if(a>10){ let a = 20; console.log(a) } console.log(a) } test() o/p: 11 20 11

hoisting not applied.

# const

block scoped eg. if-block.

Type error if we try try to assign the value again to const variables

hoisting not applied.

# var

function scoped i.e any function like test()

Variable declared with var will affect the value of variable defined outside if block.

var a=11; function test(){ if(a>10){ var a = 20; console.log(a) } console.log(a) } test() o/p: 11 20 20

hoisting applied.

# forEach loop :

Lower chance of accidental errors with forEach

Iterates through an array

forEach keeps the variable’s scope to the block

forEach is easier to read

# for loop :

You can break out of a for loop earlier.

Iterates through an array

# What is type of null :

object.

# what is undefined:

variable declared but not assigned the value returns undefined.

# Performence Improvements :

Use lazyloading for slow loading.

Use functional components for presentational components like button,modal.

safe updation.

cdn issues.

find un-neccessary re rendering by using should component update or react.memo.

Performance issues.

#Remove Duplicate Elements from Array:

let nums =[1,2,2,3];

console.log(...new Set(nums)).

#array.map method

let nums =[1,2,2,3];

nums.map(item=> item>1 )

Output: [false,true,true,true]

#array.filter method

let nums =[1,2,2,3];

nums.filter(item=> item>1 )

Output: [2,2,3]

# String to Array

const str="ABC"

console.log(str.split(""));

#Callback:

Passing the parent method into child and calling the passed method from child on any onlcick events.

# Deprecated Life Cycle Methods

ComponentWillRecieveProps() with static GetDerivedStateFromProps()

ComponentWillDidCatch(); with GetDerivedStateFromErrors

# Local storage

local storage can be used to store the user specific deatails and other information.

data persist even on closing the app or browser and Can see the data once the web app is the opened in tab.

Flipkart uses local storage to store most of the user data.

5MB to 10 MB capacity.

# Session storage

Can be used to store th session information.

data does not persist on closing the app or browser tab.

5KB capacity.

# Cookies

Can be used to store th user details like session id ,user searches and other information.

Can be used to identify the existing user or new user.

data persist on closing the app or browser tab.

# Props drilling

Passing props from parent to all childs even if only one child requirs those props.

Can be solved by using contextApi and

Props Drilling (Threading) is a concept that refers to the process you pass the data from the parent component to the exact child Component BUT in between, other components owning the props just to pass it down the chain..

# HOC

Higher-order component is a function that takes a component and returns a new component.

HOC generally used when multiple components have to use a common logic.

Eg. connect, withRouter etc.

Use.

function withNativeBaseHooks(Component) { return function WrappedComponent(props) { const myUseColorModeValue = useColorModeValue("#fff", "#1f2937"); return }; }

Wednesday, March 18, 2020

How to host ReactJs Site on GitHub Pages

Create build of your react js project by running npm run build
Goto github and login
Add react js build folder to github by create new repository
Go To setting tab
See for github Pages by scrolling down
Select master node
you will see your site is ready to be published at someurl.
wait for 1 or 2 min
Now refresh the page you will see your site is published at someurl

Saturday, March 14, 2020

Amdocs

How will you return the number of records in "Orders" table?

Customers -
Columns: customer_id (number, primary key), name (varchar), country_code (varchar), discount (number)

HOC

When working with JSX which of the following will allow you to embed a JavaScript expression in an attribute?

Ans:Please connect a monitor.

<html lang="en-us">
<head>
<style>
DIV.redBox {
box-sizing:border-box;
-moz-box-sizing:border-box; /* Firefox */
-webkit-box-sizing:border-box; /* Safari */
border:1px solid red;
float: left;
}
DIV.greenBox {
box-sizing:border-box;
-moz-box-sizing:border-box; /* Firefox */
-webkit-box-sizing:border-box; /* Safari */
border:1px solid green;
float: left;
}
</style>

</head>
<body>

<div class="redBox">
Red Box
</div>
<div class="greenBox">
Green Box
</div>

</body>
</html>

Ans:RedBox and Green Box

<html>

<style>

@media screen and (max-width:680px) {
ul.topnav li:not(:nth-child(1)):not(:nth-child(2)) {display: none;}
}

</style>

<body>
<ul class="topnav">
<li>Coffee</li>
<li>Tea</li>
<li>Milk</li>
<li>Water</li>
</ul>
</body>

</html>

ANS:

Coffee
Tea

public class Test {

public void foo() {
try{
throw new RuntimeException();
}finally{
System.out.println("In Finally Block");
}
}

public static void main(String[] args) {
try{
Test t = new Test();
t.foo();
System.out.println("Finished running");
}catch(Exception e){}
}
}

package pack2;

public abstract class CustomTest {

abstract String getCustomTestName();

}

package pack1;

import pack2.CustomTest;

public class Test extends CustomTest{

private String testName;

public String getCustomTestName(){
return testName;
}

}

public class A {

public void printStuff() {
System.out.println("printStuff in A");
}

public static void main(String[] args) {
A a = new B();
a.printStuff();
}
}

class B extends A {

public void printStuff() {
super.printStuff();
System.out.println("printStuff in B");
}
}

<html lang="en-us">
<head>
<style>
.container {
height:50px;
border:1px solid red;
width:50px;
}
</style>

</head>
<body>

<div class="container">
Hello
</div>

</body>
</html>

public class Test {

public static void foo(){
try{
throw new Exception();
}catch(MyException me){
System.out.println("In My Exception");
}catch(Exception e){
System.out.println("In Exception");
}
}

public static void main(String[] args) {
foo();
}
}

class MyException extends Exception{

}

$("[href$='.jpg']")

$("Id").on('click', printValue);

function printValue(){
...
}

function printValue(value){
...
}

A person runs 600 meters in 5 minutes. What is his speed in km per hour?

The area of a circle 64 pi. What is the diameter of the circle?

Test1 score -> 52
Test2 score -> 70
Test3 score -> 92
Test4 score -> 90
Test5 score -> 60
Test6 score -> ?

const FOO = {
num: 1,
toString: function () {
return FOO.num++;
}
}

if(FOO == 1 && FOO == 2 && FOO == 3) {
console.log('PASS');
}

function foo (a=10, b=7, c) {
return a + b + c
}

console.log(foo(10));

const NAMES = ["BMW","FIAT","KIA"];
NAMES[0] = "JEEP";
console.log(NAMES);

function foo(someNum, ...params){
return " "+(someNum) * params.length;
}

console.log(foo(100, "hello","world","ES6 Rocks!", true, 7));

var n = 6;
var foo = {
n: 5,
bar: function() {
console.log(this.n);
}
};

foo.bar();
var f = foo.bar;
f();

console.log("here");
setImmediate(function(){
console.log("we");
});
console.log("are");

var app = require("./index");

var app = require("./");

var app = require("./index.js");

class Node {

constructor (next, value) {
this._next = next
this._value = value
}

set next (next) { this._next = next }
get next () { return this._next }

set value (value) { this._value = value }
get value () { return this._value }
}

Node(1)->Node(2)->Node(3)->Node(4)->null

Node(2)->Node(3)->Node(4)->null

<form>
Name: <input type="text" size="20"><br>
Email: <input type="text" size="20"><br>
Date of birth: <input type="text" size="20">
</form>

<html>
<body>

<script>
var jsonObj = JSON.parse('{"name": "David", "age": 40}');
console.log(jsonObj.name + ", " + jsonObj.age);
</script>

</body>
</html>

var myObj = { name: "David", age: 40};
var myJSON = JSON.stringify(myObj);
console.log(myJSON);

...
xmlhttp.open("POST","newAccount.php?name=Luk&mobile=339957643",true);
xmlhttp.send();

var n = 6;
var foo = {
n: 5,
bar: function() {
console.log(this.n);
}
};

foo.bar();
var f = foo.bar;
f();

console.log("here");
setImmediate(function(){
console.log("we");
});
console.log("are");

var fs = require('fs');

try {
fs.accessSync(path, fs.F_OK);
} catch (e) {
...
}

var fs = require('fs');

fs.access(path, fs.F_OK, function(err) {
if (!err) {
...
} else {
...
}
});

ABC A2D2456 AGRE ATRGF6 ZZZ_SDFG

The longest word is: ATRGF

What is the difference between HTML5 Application Cache and regular HTML Browser Cache?

Choose the figure which will continue the series

Friday, March 13, 2020

CAA

Whoever wrote this article has to come to the body after reading it, everyone should imagine what will happen when it actually happens.

All these conspiracies have come out because of the Modi government alone and now, some people are now struggling to fulfill their wishes, * are ready to go to any level,

The only solution to this is that everyone should be united and try to understand that this is a Hindu nation. There is not a single Hindu nation on earth. Please read the following article. Your conscience should be kept vigilant. * Don't take it lightly ..... *

Until now, the CAA seems to have been opposed by ignorant or foolish people. Reading this article left a great deal of light on the head. Please all read this article till the end.

Warning: Large and eye-opening article - Also read by those who are called Left, Liberal Wagere. * Now if the eyes are not opened then there is no chance again. * As their mission accomplishes, the Liberals will also be killed like dogs in Iraq.

Some things cannot be proved in a documentary, but they are sure to be true. Just like 'Gajwa-e-Hind', 'Love Jihad', 'Project Islamistan' * - If you do not know these words, you may not read them in front. Because it is not as if the eyes were always visible. The bus documentary was not proven.

ते For the past seventeen years, people have been working on this project, 'Project Islamistan' - from one generation to the next. The dream of Islam is being transmitted from one generation to the next. * The BBC created on YouTube - a documentary called Project Islamistan has been removed three years ago. I will share exactly where to find the link. * This project is running on a large scale. It may not be possible for you to make this project huge in money * and numbers, but in order to make a country completely Islamic, these people have * forty countries experience * - you could not make a complete Hindu nation.

👺 That is to say, do not doubt the grandeur, the chaos, the money that is being poured. Missionary efforts are little more than this. They are also making huge money. *

Even though living in India for fourteen hundred years, it is not true that religion does not dissolve here. But what is the solution?

When it tried to find its origin, it was found that just as the Maratha-Rajput-Kshatriya-Jat stood to handle the invasion of the army, Brahmin, Lingayat, Awadhut, Jain Muni, Buddhist, Sadhu, Sanyasi and great saint were ready to kill the cultural invasion. The strong denial of this cultural army was clear on whether to adopt a new God, a new book, a new practice, a new kind of prayer. * The entire Indian society was protected under the sacred umbrella of cultural forces.

WorkFor the last seventy years, work has been started to lift the general public out of this sattvik shadow and stand against them. The current situation is its manifestation. * Photos of the Brahmin, the monk, the Jain muni, the neglected photos and messages will appear daily. Are we hungry for so little?

In fact, it is not a dream today to break our society * and to make it happen. * But the fear was felt when their efforts came to fruition.

👺 The society went beyond the protection of the culture and started wearing them. Christmas hats and madrasas started fresh with the missionaries. * The number of Hindus, the percentage started to decrease. Kashmir, Kerala, Bengal succeeded in liberating Hindus. *

* There was a big upset in the year * when their plot started very well. The power of India came out of the hands of the missionaries and the Gajavas to the "Hindawi Swarajya," * the Prime Minister of India, Muttasadi. With the man sitting at the top of the soil of India and in the strength of the Sangh, it was certain that all the factories would be open now. * The separation of the poor and Dalit sections of the community was not yet complete. The religious pride of Kshatriya-Maratha-Rajput-Jat was so strong that they could not be touched. But now it was impossible to stop. Missionary-gazing began with different efforts.

2 * If you remember well, a total of one Kshatriya has been targeted. The Maratha agitation, the Rajput agitation, the Jat agitation - for whatever reason - but this was intended to provoke a religious conservative group.

Modi-Shah also initiated diplomatic tricks. For the first time in the history of the new India, the demonic forces of the outside began to experience the Indian Hindu Rajasthan. Opponents of Hindu rulers threw opposition. Ever since returning home, three divorces, Gomata Raksha, 2, Ram Mandir, the only and only Hindu religion awareness agenda has been implemented.

Nevertheless, losing numbers did not diminish in that respect. Protesters were also playing big tricks. The Kshatriyas' swords were themselves trapped in various internal helplessness. They began to brainwash against the Brahmins, Lingayats, Awadhuts, Jain Munis, Buddhists, monks, and saints.

3 * Now Modi had realized that all Hindu society is united now.

👺 It is not a secret to get NRIs in the faith. CAA was built there. The issue here got irritated. Victims like Pakistan, Bangladesh and Afghanistan will raise awareness like a wounded tiger. Because they suffered the humiliation, the injustice you just imagine. And this is exactly what the Gajawa gang knows.

3 * That's it! Due to the CAA, the dream of an Islamic nation, a growing population and its soon-to-be-achieved Gajwa-e-Hind, suddenly went too far. * And the anger erupted.

Modi-Shah is bringing in Hindus, Jains, Sikhs and Buddhists from outside. It is impossible to digest it! Even more money was poured in - even ignorant Hindus became Liberals - and they joined the movement on social media with their tongues loose. But we will not give up. * Just want to keep the fight going, *

* Sustainable, because this is our country and we have to live with it. *

2 And yes, if you think that they didn't understand CAA - that's wrong. * They understand CAA well - but you still have the game on how long it takes you to understand Project Islamist, Gajwa-e-Hind, missionary and unionism. *

After reading this, * humbly requesting all Hindu community to join hands and let the unity of caste politics, Dalit-golden, high-low, multi-nationals be deprived.

3 * Receive intrusive statements in shaheen gardens and understand the facts. *

* Be one. Resist. Save the country. If the country survives, we will survive. Otherwise time does not leave anyone. The future is dire. You will have a situation similar to or worse than the Kashmiri Pandits. *

Let's get together. Let us unilaterally resist the traitors. *

* God, let us die for the country and religion. *

* Promote maximum patriotism. *

🤝🏼 🤝🏼 🤝🏼 👊🏼 🤝🏼

🙏🏽🙏🏽

Wednesday, March 11, 2020

How to Clone Git Project

W3.CSS Template

Clone GitHub Project

Sol:

Run below commands from the project root directory

 E:\Project\ui> git clone project.git

Post settings Labels Published on 3/11/20, 1:59 AM Pacific Daylight Time Permalink Location Options

How to push changed files in your GitHub project

W3.CSS Template

Push changed file To GitHub

Sol:

Run below commands from the project root directory

 E:\Project\ui> git add src/login.js

 E:\Project\ui>git commit -m "Second commit"

 E:\Project\ui>git pull

 E:\Project\ui>git push -u origin master

Wisdom Of Knowledge

Sunday, July 19, 2020

Fork Commit

Monday, May 18, 2020

Webpack file loaders to use pdf and image from outside project folder in react

Friday, March 27, 2020

spawn git error while npm install

Thursday, March 19, 2020

React Js Interview Questions

React Js and Redux Questions

Javascript Questions

Wednesday, March 18, 2020

How to host ReactJs Site on GitHub Pages

Saturday, March 14, 2020

Amdocs

Friday, March 13, 2020

CAA

Wednesday, March 11, 2020

How to Clone Git Project

Clone GitHub Project

Sol:

How to push changed files in your GitHub project

Push changed file To GitHub

Sol: